Sporting goods article

ABSTRACT

The fine-grained and/or amorphous metallic coatings are particularly suited for strong and lightweight sporting goods exposed to thermal cycling although the coefficient of linear thermal expansion (CLTE) of the metallic layer and the substrate are mismatched.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation in part of application Ser. No.12/476,455, filed on Jun. 2, 2009, now U.S. Pat. No. 8,394,507 and acontinuation of U.S. Ser. No. 12/785,524 filed May 24, 2010 now U.S. No.______.

FIELD OF THE INVENTION

This invention relates to metal-clad polymer articles comprisingpolymeric materials having a coefficient of linear thermal expansionexceeding 25×10⁻⁶ K⁻¹ in at least one direction and fine-grained(average grain-size: 2-5,000 nm) or amorphous metallic materials havinga coefficient of thermal expansion below 25×10⁻⁶ K⁻¹ enabled by theenhancement of the pull-off strength between the metallic material andthe polymer. The metal-clad polymer articles with mismatchedcoefficients of thermal expansion display good adhesion between themetallic layers and the polymeric materials as well as excellent thermalcycling performance and are suitable for structural applications.

BACKGROUND OF THE INVENTION

The invention relates to metal-clad polymer articles comprisingamorphous or fine-grained metallic coatings/layers onpolymeric-composite materials/substrates with good adhesion and thermalcycling performance for use in structural applications.

Due to their low cost and ease of processing/shaping by various means,polymeric materials, which are optionally filled with, or reinforcedwith, materials selected from the group of metals, metal alloys, and/orcarbon based materials selected from the group of graphite, graphitefibers, carbon, carbon fibers and carbon nanotubes, glass, glass fibersand other inorganic fillers, are widely used.

Applying metallic coatings or layers to the surfaces of polymer parts orvice versa is of considerable commercial importance because of thedesirable properties obtained by combining polymers and metals. Metallicmaterials, layers and/or coatings are strong, hard, tough and aestheticand can be applied to polymer substrates by various low temperaturecommercial process methods including electroless deposition techniquesand/or electrodeposition. The metal deposits must adhere well to theunderlying polymer substrate even in corrosive environments and whensubjected to thermal cycling and loads, as encountered in outdoor orindustrial service.

The prior art describes numerous processes for metalizing polymers torender them suitable for metal deposition by conditioning thesubstrate's surface to ensure metal deposits adequately bond theretoresulting in durable and adherent metal coatings. The most popularsubstrate conditioning/activation process is chemical etching.

Stevenson in U.S. Pat. No. 4,552,626 (1985) describes a process formetal plating filled thermoplastic resins such as Nylon-6®. The filledresin surface to be plated is cleaned and rendered hydrophilic andpreferably deglazed by a suitable solvent or acid. At least a portion ofthe filler in the surface is removed, preferably by a suitable acid.Thereafter electroless plating is applied to provide an electricallyconductive metal deposit followed by applying at least one metalliclayer by electroplating to provide a desired wear resistant and/ordecorative metallic surface. Stevensen provides no information onthermal cycling performance or adhesion strength.

Leech in U.S. Pat. No. 4,054,693 (1977) discloses processes for theactivation of resinous materials with a composition comprising water,permanganate ion and manganate ion at a pH in the range of 11 to 13exhibiting superior peel strengths following electroless metaldeposition. Leech provides no information on thermal cyclingperformance, and adhesion strength is exclusively measured using a peeltest.

Nishizawa in U.S. Pat. No. 5,185,185 (1993) discloses methods forpretreating polymeric resin molded articles molded from various resinsand a glass-reinforcing agent such as glass fibers by (i) treating theresin molded article by immersion in an oxidative acid solution, (ii)treating the resulting resin molded article by immersion in an organicpolar solvent-containing liquid, and (iii) treating the resulting resinmolded article by immersion in a solvent which can dissolve one or bothof the glass reinforcing agent and one or more of the otherthermoplastic resins. The use of ammonium fluoride as glass fiberetchant is shown to enhance adhesion. Nishizawa provides no informationon thermal cycling performance and reports peel strength data≦1.5 kg/cm(≦14.7 N/cm).

Yates in U.S. Pat. No. 5,863,410 (1999) describes an electrolyticprocess for producing copper foil having a matte surface with micropeakswith a height not greater than about 200 microinches (˜5 micron)exhibiting a high peel strength when bonded to a polymeric substrate.

Various patents address the fabrication of articles for a variety ofapplications:

Watanabe in U.S. Pat. No. 6,996,425 (2006) describes a cellulartelephone housing formed from a polymeric material by molding, whereinthe base is coated with a metal multi layer to about 10 micronthickness, including a lower metal layer (adjacent to the polymersubstrate) made of a ductile metal such as Cu and an upper metal layermade of a less ductile metal such as Ni to achieve high strength,rigidity and shock resistance. The ductile metal layer is 4-5 timesthicker than the upper metal layer. Watanabe provides no information onthermal cycling performance or adhesion strength.

Erb in U.S. Pat. No. 5,352,266 (1994), and U.S. Pat. No. 5,433,797(1995), assigned to the same applicant, describe a process for producingnanocrystalline materials, particularly nano crystalline nickel basedmaterials. The nanocrystalline material is electrodeposited onto thecathode in an aqueous electrolyte by the application of a pulsedcurrent.

Palumbo in US 2005/0205425 A1 (2002) and DE 10,288,323 (2005), assignedto the same applicant, discloses a process for forming coatings orfreestanding deposits of nanocrystalline metals, metal alloys or metalmatrix composites. The process employs tank plating, drum plating orselective plating processes using aqueous electrolytes and optionally anon-stationary anode or cathode. Nanocrystalline metal matrix compositesare disclosed as well.

Tomantschger in US 2009/0159451 A1, assigned to the same applicant,discloses variable property deposits of fine-grained and amorphousmetallic materials, optionally containing solid particulates.

Palumbo in U.S. Pat. No. 7,320,832 (2008), assigned to the sameapplicant, discloses means for matching the coefficient of thermalexpansion (CTE) of fine-grained metallic coating to the one of thesubstrate by adjusting the composition of the alloy and/or by varyingthe chemistry and volume fraction of particulates embedded in thecoating. The fine-grained metallic coatings are particularly suited forstrong and lightweight articles, precision molds, sporting goods,automotive parts and components exposed to thermal cycling and includeselected polymeric substrates. Maintaining low CTEs (<25×10⁻⁶ K⁻¹) andmatching the CTEs of the fine-grained metallic coating with the CTEs ofthe substrate minimizes dimensional changes during thermal cycling andpreventing delamination. Palumbo provides no information on the adhesionstrength.

Palumbo in U.S. Pat. No. 7,354,354 (2008), assigned to the sameapplicant, discloses lightweight articles comprising a polymericmaterial at least partially coated with a fine-grained metallicmaterial. The fine-grained metallic material has an average grain sizeof 2 nm to 5,000 nm, a thickness between 25 micron and 5 cm, and ahardness between 200 VHN and 3,000 VHN. The lightweight articles arestrong and ductile and exhibit high coefficients of restitution and ahigh stiffness and are particularly suitable for a variety ofapplications including aerospace and automotive parts, sporting goods,and the like. Palumbo provides no information on thermal cyclingperformance or adhesion strength. To enhance the adhesion of themetallic coating the surface to be coated is roughened by any number ofsuitable means including, e.g., mechanical abrasion, plasma and chemicaletching.

Andri in WO 2009/045431 describes portable electronic devices comprisinga structural synthetic resin and structural coatings of fine-grainedmetallic materials for added strength, rigidity and impact resistance.According to Andri the metal adheres well to the synthetic resin withoutany special treatment; however, a method for improving adhesion can beused including abrasion, addition of adhesion promotion agents, chemicaletching, functionalization of the surface by exposure to plasma and/orradiation or any combination of these. Andri provides no information onthermal cycling performance or adhesion strength.

Andri in WO 2009/073435 describes automotive parts with a compositioncomprising partially aromatic polyamide (PAP), aliphatic polyamideand/or polymeric toughener and alkaline earth metal carbonate e.g.calcium carbonate. The polymer is activated using mechanical and/orchemical etching, specifically acidic materials such as sulfochromicacid, hydrochloric acid or sulfuric acid.

SUMMARY OF THE INVENTION

It is an objective of the present invention to provide strong,lightweight metal-clad polymer articles for use in structuralapplications, e.g., in automotive, aerospace and defense applications,industrial components, electronic equipment or appliances and sportinggoods, molding applications and medical applications, having a metalliclayer applied to a polymeric substrate with enhanced adhesion, pull-offstrength, peel strength, shear strength and thermal cycling performance.

It is an objective of the invention to provide a metallic coating/layerselected from the group of amorphous, fine-grained (defined as anaverage grain size between 2 and 5,000 nm) and coarse-grained metal(defined as an average grain size>5 microns), metal alloy or metalmatrix composites. The metallic coating/layer is applied to the polymersubstrate by a suitable metal deposition process. Preferred metaldeposition processes include low temperature processes, i.e., processesoperating below the softening and/or melting temperature of the polymersubstrates, selected from the group of electroless deposition,electrodeposition, physical vapor deposition (PVD), chemical vapordeposition (CVD) and gas condensation. Alternatively, the polymer can beapplied to a metallic layer. The metallic material represents between 1and 95% of the total weight of the article.

It is an objective of the present invention to provide single ormultiple structural metallic layers having a microstructure selectedfrom the group of fine-grained, amorphous, graded and layeredstructures, which have a total thickness in the range of between 2.5micron and 5 cm, preferably between 25 micron and 2.5 cm and morepreferably between 50 micron and 500 micron.

It is an objective of this invention to provide articles comprisingfine-grained and/or amorphous metallic coatings which are, at least inpart, graded and/or layered, i.e., “variable properety metalliccoatings”.

In addition to providing improved mechanical properties it is anobjective of the invention to apply a metallic layer or metallic layersto provide further functional properties to the metal-clad polymerarticle including thermal conductivity and heat-dissipation, magneticproperties including, but not limited to, electromagnetic interference(EMI) shielding and radio-frequency interference (RFI) shielding,antimicrobial properties, superhydrophobicity and self cleaningproperties.

Furthermore it is an objective to optionally apply topcoats to themetallic layers or exposed polymeric substrate with decorative coatingssuch as chromium plate or paint.

It is an objective of the invention to provide a metal-clad polymerarticle comprising a shaped or molded polymer component comprisingpolymeric resins or polymeric composites including, but not limited to,epoxies, ABS, polypropylene, polyethylene, polystyrene, vinyls,acrylics, polyamide and polycarbonates. Suitable fillers include carbon,ceramics, oxides, carbides, nitrides, polyethylene, fiberglass and glassin suitable forms including fibers and powders. The polymeric substratehas a room temperature coefficient of linear thermal expansion (CLTE) inat least one direction of between 30×10⁻⁶ K⁻¹ and 500×10⁻⁶ K⁻¹, e.g., ofbetween 30×10⁻⁶ K⁻¹ and 250×10⁻⁶ K⁻¹

It is an objective of this invention to provide a fine-grained and/oramorphous metallic layer having a room temperature CLTE in alldirections of less than 25×10⁻⁶ K⁻¹, for example, in the range between−5.0×10⁻⁶ K⁻¹ and 25×10⁻⁶ K⁻¹. The metallic layer comprises one or moreelements selected from the group of Ag, Al, Au, Co, Cr, Cu, Fe, Ni, Mo,Pb, Pd, Pt, Rh, Ru, Sn, Ti, W, Zn and Zr. Metal matrix compositesconsist of fine-grained and/or amorphous pure metals or alloys withsuitable particulate additives. The latter additives include powders,fibers, nanotubes, flakes, metal powders, metal alloy powders and metaloxide powders of Al, Co, Cu, In, Mg, Ni, Si, Sn, V, and Zn; nitrides ofAl, B and Si; C (graphite, diamond, nanotubes, Buckminster Fullerenes);carbides of B, Cr, Bi, Si, W; and self lubricating materials such asMoS₂ or organic materials e.g. PTFE. The fine-grained and/or amorphousmetallic material has a high yield strength (300 MPa to 2,750 MPa) andductility (1-15%).

It is an objective of the invention to utilize the enhanced mechanicalstrength and wear properties of fine-grained metallic coatings/layerswith an average grain size between 1 and 5,000 nm, e.g., between 2 and500 nm, and/or amorphous coatings/layers and/or metal matrix compositecoatings exhibiting a coefficient of linear thermal expansion (CLTE) inthe range of −5×10⁻⁶ K⁻¹ to 25×10⁻⁶ K⁻¹ at room temperature in alldirections. Metal matrix composites (MMCs) in this context are definedas particulate matter embedded in a fine-grained and/or amorphous metalmatrix. MMCs can be produced e.g. in the case of using an electrolessplating or electroplating process by suspending particles in a suitableplating bath and incorporating particulate matter into the deposit byinclusion or, e.g., in the case of cold spraying, by addingnon-deformable particulates to the powder feed.

It is another objective of the invention to provide laminate articles,e.g., a metal-clad polymer article, comprising (i) a polymeric materialwhich at room temperature has a coefficient of linear thermal expansionin the range between 30×10⁻⁶ K⁻¹ and 250×10⁻⁶ K⁻¹ in at least onedirection and (ii) a metallic material having a microstructure which isfine-grained with an average grain size between 2 and 5,000 inn and/oran amorphous microstructure; the metallic material being in the form ofa metallic layer having a thickness between 10 microns and 2.5 cm and acoefficient of linear thermal expansion in all directions in the rangebetween −5.0×10⁻⁶ K⁻¹ and 25×10⁻⁶ K⁻¹; the coefficient of linear thermalexpansion in all directions of (ii) being at least 20% less than thecoefficient of linear thermal expansion in at least one direction of(i); the laminate article and metal-clad polymer article exhibiting nodelamination and the displacement of said metallic material relative tothe polymeric material or relative to any intermediate layer being lessthan 2% after said articles has been exposed to at least one temperaturecycle according to ASTM B553-71 service condition 1, 2, 3 or 4 andexhibiting a pull-off strength between the polymeric material and themetallic material or between any intermediate layer(s) and the metallicmaterial exceeding 200 psi as determined by ASTM D4541-02 method A-E.

It is another objective of the invention to pretreat the surface ofpolymeric and/or the metallic material to achieve excellent adhesionbetween metallic layer and the polymer material is required to pass thethermal cycling tests specified without failure such as delamination.

It is an objective of the invention to suitably roughen or texture atleast one of the surfaces to be mated to form specific surfacemorphologies, termed “anchoring structures” or “anchoring sites”. Theelimination of smooth surfaces provides for additional surface area foradhesion, increases the bond strength and reduces the risk ofdelamination and/or blistering.

It is an objective of the invention to provide a polymer-metal interfaceby creating suitable anchoring structures prior to applying the metal tothe polymer or vice versa. The population of anchoring sites such asrecesses/protrusions and the like enhances the physical bond between thepolymer and the metal. It is an objective to create anchoring structuresat the interface between the polymer and the metal exceeding 10 per cm,preferably exceeding 100 per cm and more preferably exceeding 1,000 percm and up to 100,000 per cm, preferably up to 1,000,000 per cm and morepreferably up to 10,000,000 per cm. Suitable anchoring structures havean average depth and average diameter/width in the range of between 0.01and 5,000 micron, preferably in the range of between 0.05 and 500micron. The shape of the anchoring structures preferably isirregular/random providing for a “locked in” bond between the twosurfaces to be mated, e.g., as generated by metal deposition into a“polymer cavity” formed like and ink bottle, i.e., a narrow neck on thesurface leading to a wide base in the bulk polymer. The overall strengthof the metal-clad polymer article is governed by the bond strengthbetween the polymer substrate and the immediately adjacent metalliclayer.

It is another objective of the invention to provide laminate articlesfor components exposed to temperature cycling during use therebyincreasing the need for acceptable CLTE mismatch between polymer and themetallic materials.

It is an objective of the invention to provide a polymeric or metallicsubstrate with an interface layer having a surface roughness Ra in therange of between 0.01 μm and 500 μm and/or Ry (Ry_(max) according toDIN) in the range of 0.01 μm and 5,000 μm. In the context of thisapplication the average surface roughness Ra is defined as thearithmetic means of the absolute values of the profile deviations fromthe mean line and Ry (Ry_(max) according to DIN) is defined as thedistance between the highest peak and the lowest valley of the interfacesurface.

It is an objective of the invention to apply a fine-grained and/oramorphous metallic coating to at least a portion of the surface of apart made substantially of polymer(s) and/or glass fiber compositesand/or carbon/graphite fiber composites including carbon fiber/epoxycomposites, optionally after metalizing the surface (layer thickness≦5micron, preferably ≦1 micron) with a thin layer of nickel, copper,silver or the like for the purpose of enhancing the electricalconductivity of the substrate surface. The fine-grained and/or amorphouscoating is always substantially thicker (≧10 micron) than the metalizinglayer. Any metalizing intermediate layer has a coefficient of linearthermal expansion (CLTE) in the range of −5×10⁻⁶ K⁻¹ to 25×10⁻⁶ K⁻¹ atroom temperature in all directions.

According to this invention patches or sleeves which are not necessarilyuniform in thickness can be employed in order to, e.g., enable ametallic thicker coating on selected sections or areas of articlesparticularly prone to heavy use such as in the case of selectedaerospace and automotive components, sporting goods, consumer products,electronic devices and the like.

It is an objective of the invention to achieve adhesion strength asmeasured using ASTM D4541-02 Method A-E “Standard Test Method forPull-Off Strength of Coatings Using Portable Adhesion Testers” betweenthe metallic material/coating and the polymer material/substrate whichexceeds 200 psi, preferably 300 psi, preferably 500 psi and morepreferably 600 psi and up to 6,000 psi.

It is an objective of the invention to suitably precondition the polymersubstrate surface to enhance the adhesion between the polymer substrateand the metallic layer and achieve a strong interfacial bond between thepolymer and the metal.

It is an objective of the invention to improve the adhesion between thepolymeric substrate and the metallic layer by a suitable heat treatmentof the metal-clad article for between 5 minutes and 50 hours at between50 and 200° C.

It is an objective of this invention to provide articles composed offine-grained and/or amorphous metallic coatings on composite polymericsubstrates capable of withstanding 1, preferably 5, more preferably 10,more preferably 20 and even more preferably 30 temperature cycleswithout failure according to ANSI/ASTM specification B604-75 section 5.4(Standard Recommended Practice for Thermal Cycling Test for Evaluationof Electroplated Plastics ASTM B553-71) for service condition 1,preferably service condition 2, preferably service condition 3 and evenmore preferably for service condition 4.

It is a further objective of the invention to render the metalliccoatings super-hydrophobic and self-cleaning by applying a thin coat ofa poorly wetting or non wetting material to the outer surface including,but not limited to, paint.

It is a further objective of the invention to render the metalliccoatings hydrophobic, preferably super-hydrophobic and self cleaning byrendering the metallic coating poorly wetting or non wetting (“flatsheet contact angle” for deionized water of ≧85°) including, but notlimited to, applying metal matrix composite (MMC) outer layerscontaining non-wetting particulate additions.

It is a further objective of the invention to imprint anchoringstructures on the polymer surface not be covered by the metallic coatingto achieve a hydrophobic surface, i.e., raise the contact angle forwater by ≧10°, preferably by ≧20°, more preferably by ≧25°, and evenmore preferably by ≧30° when compared to the contact angle measured onthe flat polymer surface.

It is a further objective of the invention to imprint anchoringstructures on portions of the polymer surface not be covered by themetallic coating to raise the contact angle for water of said polymericsurface to ≧100°, preferably over ≧110° and more preferably ≧120° andrender the polymeric surface self cleaning.

It is an objective of the invention to retain at least part of thepolymer surface structures in the outer surface of the metallic coatingby avoiding leveling/filling of the recesses to obtain a satin metalfinish, defined as a surface roughness of Ra≧0.5 micron.

It is an objective of the invention to provide lightweightpolymer/metal-hybrid articles wherein portions of the polymericsubstrate and up to substantially the entire polymer substrate surfaceis imprinted with anchoring structures followed by selectively coveringat least a portion of the polymer surface with the fine-grained oramorphous metallic coating layer(s), while not covering at least aportion of said imprinted polymer substrates to achieve hydrophobicity(contact angle for water of ≧90°, preferably super-hydrophobicity(contact angle for water of ≧140°) and self-cleaning behavior (tiltangle of ≦5°), in the treated portions of the polymer substrate itself.

It is an objective of this invention to provide lightweightpolymer/metal-hybrid articles with increased strength, stiffness,durability, wear resistance, thermal conductivity and thermal cyclingcapability.

It is an objective of this invention to provide polymer articles, coatedwith fine-grained and/or amorphous metallic layers that are stiff,lightweight, resistant to abrasion, resistant to permanent deformation,do not splinter when cracked or broken and are able to withstand thermalcycling without degradation, for a variety of applications including,but not limited to: (i) applications requiring cylindrical objectsincluding gun barrels; shafts, tubes, pipes and rods; golf and arrowshafts; skiing and hiking poles; various drive shafts; fishing poles;baseball bats, bicycle frames, ammunition casings, wires and cables andother cylindrical or tubular structures for use in commercial goods;(ii) medical equipment including orthopedic prosthesis and surgicaltools, crutches, wheel chairs, implants, pacemakers, hearing aids; (iii)sporting goods including golf shafts, heads and faceplates; lacrossesticks; hockey sticks; skis and snowboards as well as their componentsincluding bindings; racquets for tennis, squash, badminton; bicycleparts; (iv) components and housings for electronic equipment includinglaptops; televisions and handheld devices including cell phones;personal digital assistants (PDAs) devices; walkmen; discmen; digitalaudio players, e-mail functional telephones; digital cameras and otherimage recording devices; audio and/or video recording devices; two-wayradios; televisions and remote controls; (v) automotive componentsincluding heat shields; cabin components including seat parts, steeringwheel and armature parts; fluid conduits including air ducts, fuelrails, turbocharger components, oil, transmission and brake parts, fluidtanks and housings including oil and transmission pans; cylinder headcovers; spoilers; grill-guards and running boards; brake, transmission,clutch, steering and suspension parts; brackets and pedals; mufflercomponents; wheels; brackets; vehicle frames; spoilers; fluid pumps suchas fuel, coolant, oil and transmission pumps and their components;housing and tank components such as oil, transmission or other fluidpans including gas tanks; electrical and engine covers; (vi)industrial/consumer products and parts including linings on hydraulicactuator, cylinders and the like; drills; files; knives; saws; blades;sharpening devices and other cutting, polishing and grinding tools;housings; frames; hinges; sputtering targets; antennas as well aselectromagnetic interference (EMI) shields, radio frequency interference(RFI) shields; (vii) molds and molding tools and equipment; (viii)aerospace parts and components including wings; wing parts includingflaps and access covers; structural spars and ribs; propellers; rotors;rotor blades; rudders; covers; housings; fuselage parts; nose cones;landing gear; lightweight cabin parts; cryogenic storage tanks; ductsand interior panels; and (ix) military products including ammunition,armor as well as firearm components, and the like; that are coated withfine-grained and/or amorphous metallic layers that are stiff,lightweight, resistant to abrasion, resistant to permanent deformation,do not splinter when cracked or broken and are able to withstand thermalcycling without degradation.

It is an objective of this invention to at least partially coat theinner or outer surface of parts including complex shapes withfine-grained and/or amorphous metallic materials that are strong,lightweight, have high stiffness (e.g. resistance to deflection andhigher natural frequencies of vibration) and are able to withstandthermal cycling without degradation.

Accordingly, the invention in one embodiment denoted the firstembodiment, is directed to a metal-clad polymer article comprising:

-   -   (i) a polymeric material which at room temperature has a        coefficient of linear thermal expansion in the range between        30×10⁻⁶ K⁻¹ and 250×10⁻⁶ in at least one direction; and    -   (ii) a metallic material having a microstructure which is        fine-grained with an average grain size between 2 and 5,000 nm        and/or an amorphous microstructure, the metallic material being        in the form of a metallic layer having a thickness between 10        micron and 2.5 cm and a coefficient of linear thermal expansion        in all directions in the range between −5.0×10⁻⁶ K⁻¹ and 25×10⁻⁶        K⁻¹;    -   (iii) with or without at least one intermediate layer between        the polymeric material and the metallic material (having a        coefficient of linear thermal expansion in all directions in the        range between −5.0×10⁶ K⁻¹ and 250×10⁻⁶ K⁻¹;    -   (iv) an interface between the polymeric material and the        metallic material or an interface between the polymeric material        and any intermediate layer(s) and an interface between any        intermediate layer(s) and the metallic material;    -   (v) anchoring structure at said interface(s) comprising recesses        and/or protrusions to increase the interface area and provide        enhanced physical bond at the interface between the polymeric        material and the metallic material or at the interface between        the polymeric material and any intermediate layer(s) and at the        interface between any intermediate layer(s) and the metallic        material;    -   (vi) said metal-clad polymer article exhibiting no delamination        and the displacement of said metallic material of (ii) relative        to the polymeric material of (i) or relative to any intermediate        layer(s) being less than 2% after said article has been exposed        to at least one temperature cycle according to ASTM B553-71        service condition 1, 2, 3 or 4; and (vii) said metal-clad        polymer article exhibiting a pull-off strength between the        polymeric material of (i) and the metallic material of (ii) or        any intermediate layer exceeding 200 psi as determined by ASTM        D4541-02 Method A-E; and    -   (viii) said metal-clad polymer article or portion thereof having        a yield strength and/or ultimate tensile strength of between 10        and 7,500 MPa and an elastic limit between 0.5 and 30%.

Accordingly, the invention in another embodiment, denoted the secondembodiment, is directed to a metal-clad polymer article comprising:

-   -   (i) a polymeric material which at room temperature has a        coefficient of linear thermal expansion in the range between        30×10⁻⁶ K⁻¹ and 250×10⁻⁶ K⁻¹, in at least one direction;    -   (ii) a metallic material having a microstructure which is        fine-grained with an average grain size between 2 and 5,000 nm        and/or an amorphous microstructure, the metallic material being        in the form of a metallic layer having a thickness between 10        micron and 2.5 cm and a coefficient of linear thermal expansion        in all directions in the range between −5.0×10⁻⁶ K⁻¹ and 25×10⁻⁶        K⁻¹; the coefficient of linear thermal expansion in all        directions being at least 20% less than the coefficient of        linear thermal expansion in at least one direction of (i);    -   (iii) with or without at least one intermediate layer between        the polymeric material and the metallic material having a        coefficient of linear thermal expansion in all directions in the        range between −5.0×10⁶ K⁻¹ and 250×10⁻⁶ K⁻¹; the coefficient of        linear thermal expansion in all directions of (ii) being at        least 20% less than the coefficient of linear thermal expansion        in at least one direction of (i);    -   (iv) an interface between the polymeric material and the        metallic material or an interface between the polymeric material        and any intermediate layer(s) and an interface between any        intermediate layer(s) and the metallic material;    -   (v) anchoring structure at said interface(s) comprising recesses        and/or protrusions to increase the interface area and provide        enhanced physical bond at the interface between the polymeric        material and the metallic material or at the interface between        the polymeric material and any intermediate layer;    -   (vi) said metal-clad polymer article exhibiting no delamination        and the displacement of said metallic material of (ii) relative        to the polymeric material of (i) being less than 2% after said        article has been exposed to at least one temperature cycle        according to ASTM B553-71 service condition 1, 2, 3 or 4; and    -   (vii) said metal-clad polymer article exhibiting a pull-off        strength between the polymeric material of (i) and the metallic        material of (ii) or any intermediate layer exceeding 200 psi as        determined by ASTM D4541-02 Method A-E; and    -   (viii) said metal-clad polymer article or portion thereof having        a yield strength and/or ultimate tensile strength of between 10        and 7,500 MPa and an elastic limit between 0.5 and 30%.

Accordingly the invention in still another embodiment, denoted the thirdembodiment, is directed to a method for preparing the metal-clad polymerarticle of the first embodiment comprising:

-   -   (i) providing a polymeric material which at room temperature has        a coefficient of linear thermal expansion exceeding 30×10⁻⁶ K⁻¹        in at least one direction.    -   (ii) providing a metallic material having a microstructure which        is fine-grained with an average grain size between 2 and 5,000        nm and/or an amorphous microstructure where the metallic        material is in the form of a metallic layer having a thickness        between 10 microns and 2.5 cm and a coefficient of linear        thermal expansion in all directions in the range between        −5.0×10⁻⁶ K⁻¹ and 25×10⁻⁶ K⁻¹,    -   (iii) optionally providing at least one electrically conductive        or electrically nonconductive adhesive intermediate layer,    -   (iv) providing interface(s) between the polymeric material and        the metallic layer and between the polymeric material and any        intermediate layer and between any intermediate layer and the        metallic layer and between any adjacent intermediate layers,    -   (v) providing anchoring structure at said interfaces to anchor        polymeric material to metallic layer or polymeric material to        any intermediate layer, and metallic layer to any intermediate        layer or in the case of intermediate layers to anchor one        intermediate layer to another.

In one aspect of the third embodiment the coefficient of linear thermalexpansion in all directions of the metallic layer and of anyintermediate layer(s) is at least 20% less than the coefficient oflinear thermal expansion in at least one direction of the polymericmaterial. In one case of the third embodiment a metallic layer isdeposited onto a polymeric substrate having anchoring structureassociated therewith by electrodeposition, physical vapor deposition(PVD), and chemical vapor deposition (CVD). In another case of the thirdembodiment the polymeric material is applied to the metallic layerhaving anchoring structure associated therewith.

Accordingly the invention in still another embodiment, denoted thefourth embodiment, is directed to a polymeric material which at roomtemperature has a coefficient of linear thermal expansion in the rangebetween 30×10⁻⁶ K⁻¹ and 250×10⁻⁶ K⁻¹ in at least one direction:

-   -   (i) said polymer material having one or more outer surfaces;    -   (ii) anchoring structures embossed in at least a portion of said        outer surface(s) of said polymeric material comprising recesses        and/or protrusions;    -   (iii) said embossed portions exhibiting a contact angle for        water of at least 100 degrees; and    -   (iv) at least some of said portions being coated with a metallic        material having a microstructure which is fine-grained with an        average grain size between 2 and 5,000 nm and/or an amorphous        microstructure.

Accordingly the invention in still another embodiment, denoted the fifthembodiment, is directed to a metal-clad polymer article comprising:

-   -   (i) a polymeric substrate at least partially imprinted with        anchoring structures to raise the contact angle for water in the        imprinted areas to ≧100°,    -   (ii) a metallic material coating portions of said imprinted        polymeric substrate having a microstructure which is        fine-grained with an average grain size between 2 and 5,000 nm        and/or an amorphous microstructure; and    -   (iii) with or without at least one intermediate layer between        the portions of the polymeric material coated with the metallic        material.

Accordingly the invention in still another embodiment, denoted the sixthembodiment, is directed to a metal-clad polymer article comprising:

-   -   (i) a polymeric substrate at least partially imprinted with        anchoring structures to raise the contact angle for water in the        imprinted areas by ≧10° when compared to the flat polymeric        substrate surface of the same composition,    -   (ii) a metallic material coating portions of said polymeric        substrate having a microstructure which is fine-grained with an        average grain size between 2 and 5,000 nm and/or an amorphous        microstructure; and    -   (iii) with or without at least one intermediate layer between        the portions of the polymeric material coated with the metallic        material.

As used herein, the terms “laminate article” and “metal-clad article”means an item which contains at least one polymeric layer and at leastone metallic layer in contact with each other.

As used herein, the term “coating” means deposit layer applied to partor all of an exposed surface of a substrate.

As used herein, the term “coating thickness” or “layer thickness” refersto depth in a deposit direction.

As used herein, the term “variable property” is defined as a depositproperty including, but not limited to, chemical composition, grainsize, hardness, yield strength, Young's modulus, resilience, elasticlimit, ductility, internal stress, residual stress, stiffness,coefficient of thermal expansion, coefficient of friction, electricalconductivity, magnetic coercive force, and thickness, being varied bymore than 10% in the deposition direction and/or at least in one of thelength or width directions. “Layered structures” have said depositproperty varied by more than 10% between sublayers and the sublayerthickness ranges from 1.5 nm to 1,000 microns.

As used herein, “anodically assisted chemical etching” means that thesurface of a polymeric substrate to be coated is activated by applyinganodic polarization to the substrate which is submersed in a chemicaletching solution thereby simultaneously chemically and electrochemicallyactivating the surface to achieve a superior bond between the substrateand the subsequently applied coating.

As used herein the “inherent contact angle” or “intrinsic contact angle”is characterized by the contact angle for a liquid measured on ahorizontal, flat and smooth surface not containing any surfacestructures.

As used herein the term “smooth surface” is characterized by a surfaceroughness Ra≦0.25 microns.

As used herein, “super-hydrophobicity” refers to a contact angle fordeionized water at room temperature≧140° and “self-cleaning” refers to atilt angle of ≦5°.

As used herein, the term “tile angle” or “roll-off angle” means thesmallest angle between a surface containing a water droplet and thehorizontal surface at which the droplet commences to and keeps rollingoff.

As used herein “texturing” or “roughening” the surface means that thenature of a surface is not smooth but has a distinctive rough texturecreated by the surface structures purposely introduced to render thesurface fluid repellant.

As used herein, the term “anchoring structures” refers to surfacefeatures including recesses/protrusions purposely created in theinterface between the polymeric material and the metallic material layeror the interface between the polymeric material and the intermediatelayer, e.g., in the polymeric material or in the metallic material layeror in any intermediate layer, to enhance their bond strength.

As used herein, the term “population of anchoring structures” refers tonumber of surface features per unit length or area. The “linearpopulation of anchoring structures” can be obtained by counting thenumber of features, e.g. on a cross sectional image and normalizing itper unit length, e.g., per cm. The average “areal population ofanchoring structures” is the square of the average linear population,e.g., expressed in cm² or mm². Alternatively, the average areal densitycan be obtained by counting the number of features visible in an opticalmicrograph, SEM image or the like and normalizing the count for themeasurement area.

As used herein, “surface roughness”, “surface texture” and “surfacetopography” mean an irregular surface topography such as a polymermaterial or metallic material layer or intermediate layer surfacecontaining anchoring structures. Surface roughness consists of surfaceirregularities which result from the various surface preconditioningmethods used such as mechanical abrasion and etching to create suitableanchoring structures. These surface irregularities/anchoring structurescombine to form the “surface texture” which directly influences the bondstrength achieved between the polymeric article and the metallic layer.

In practice there are many different parameters used for analyzingsurface finish, and many more have been developed for specialproducts/circumstances. The parameter most frequently used in NorthAmerica for surface roughness is Ra. It measures the average roughnessby comparing all the peaks and valleys to the mean line, and thenaveraging them all over the entire length that a stylus is draggedacross the surface. It's also referred to as CLA (center line average)and AA (area average). Benefits of using the Ra method are itssimplicity and its widespread use. The RMS (root mean square) of a givensurface typically runs about 10% higher than its equivalent Ra (averageroughness) value.

In reality, however, the Ra value neither provides a detailed enoughdescription of a surface finish of a part nor an absolute indication ofthe achievable adhesion strength when bonded to another material.Another parameter that can be useful is Ry_(max) formerly called justR_(max). This is an International Organization for Standardization (ISO)standard that measures the distance between the highest peak and thelowest valley over a cutoff length. This is, however, a sensitive methodand, if over the measurement length a scratch or imperfection isencountered, the reading may be meaningless. Similarly, Ry depicts themaximum roughness depth.

Another parameter most widely used in Europe is Rz, or mean roughnessdepth. The Rz ISO standard is also called “Ten Point Average Roughness”.It averages the height of the five highest peaks and the depth of thefive lowest valleys over the measuring length, using an unfilteredprofile. The Rz DIN standard averages the highest point and lowest pointover five cutoffs.

As used herein, the term “intermediate layer” means a layer locatedbetween and in intimate contact with a polymeric material substrate anda metallic layer or another intermediate layer. Examples of intermediatelayers include “intermediate conductive layers” or “metalizing layers”applied to the surface of the polymer material to enhance the surface toenable electroplating. The intermediate layer can comprise a metalliclayer, an oxide layer, a polymeric material layer such as an adhesivelayer, or a polymer layer with conductive particulates embedded therein.

As used herein, the term “molding” of polymers means shaping of anarticle to its near final shape using injection molding, blow molding,compression molding, transfer molding, rotational molding, extrusion,thermoforming, vacuum forming or other suitable shaping methodsavailable for polymers.

As used herein “delamination” means failure of a laminated structure bythe separation between two layers comprised of different chemicalcompositions resulting in the physical splitting of the layers.

As used herein “displacement” means the difference between a laterposition of a coating and its original position on a substrate caused bythe relative movement of a coating, e.g., induced by thermal cycling oflaminates composed of layers with different CLTEs.

According to one aspect of the present invention an article is providedby a process which comprises the steps of, positioning the metallic ormetallized work piece to be plated in a plating tank containing asuitable electrolyte and a fluid circulation system, providingelectrical connections to the work piece/cathode to be plated and to oneor several anodes and plating a structural layer of a metallic materialwith an average grain size of equal to or less than 5,000 nm on thesurface of the metallic or metallized work piece using suitable directcurrent (D.C.) or pulse electrodeposition processes described, e.g., inthe copending application US 2005/020542, published Sep. 22, 2005 (DE10,228,323; 2005).

Metal-clad polymer articles of the invention comprise fine-grainedand/or amorphous metallic layers having low CLTEs e.g. −5.0×10⁻⁶ K⁻¹ to25×10⁻⁶ K⁻¹ in all directions, having a layer thickness of at least0.010 mm, preferably more than 0.020 mm, more preferably more than 0.030mm and even more preferably more that 0.050 mm on polymeric substrateshaving CLTEs in at least one direction of between 30×10⁻⁶ K⁻¹ to500×10⁻⁶ K⁻¹.

Articles of the invention comprise a single or several fine-grainedand/or amorphous metallic layers applied to the substrate as well asmulti-layer laminates composed of alternating layers of fine-grainedand/or amorphous metallic layers and polymeric substrates.

The fine-grained metallic coatings/layers have a grain size under 5 μm(5,000 nm), preferably in the range of 5 to 1,000 nm, more preferablybetween 10 and 500 nm. The grain size can be uniform throughout thedeposit; alternatively, it can consist of layers with differentmicrostructure/grain size. Amorphous microstructures and mixedamorphous/fine-grained microstructures are within the scope of theinvention as well.

According to this invention, the entire polymer surface can be coated;alternatively, metal patches or sections can be formed on selected areasonly (e.g. golf club face plates or sections of golf club shafts, arrowsor polymer cartridge casings), without the need to coat the entirearticle.

According to this invention metal patches or sleeves which are notnecessarily uniform in thickness and/or microstructure can be depositedin order to e.g. enable a thicker coating on selected sections orsections particularly prone to heavy use such as golf club face or soleplates, the tip end of fishing poles, arrows and shafts for golf clubs,skiing or hiking poles, polymer cartridge casings, automotive componentsand the like.

According to this invention laminate articles in one aspect comprisefine-grained and/or amorphous metal layers on carbon-fiber and/or glassfiber filled polymeric substrates.

The following listing further defines the laminate article/metal-cladarticle of the invention:

Polymeric Substrate Specification:

Minimum coefficient of linear thermal expansion in at least onedimension [10⁻⁶ K⁻¹]: 20; 25; 30; 50Maximum coefficient of linear thermal expansion in at least onedimension [10⁻⁶ K⁻¹]: 250; 500Polymeric materials comprise at least one of: unfilled or filled epoxy,phenolic or melamine resins, polyester resins, urea resins;thermoplastic polymers such as thermoplastic polyolefins (TPOs)including polyethylene (PE) and polypropylene (PP); polyamides, mineralfilled polyamide resin composites; polyphthalamides, polyphthalates,polystyrene, polysulfone, polyimides; neoprenes; polybutadienes;polyisoprenes; butadiene-styrene copolymers; poly-ether-ether-ketone(PEEK); polycarbonates; polyesters; liquid crystal polymers such aspartially crystalline aromatic polyesters based on p-hydroxybenzoic acidand related monomers; polycarbonates; acrylonitrile-butadiene-styrene(ABS); chlorinated polymers such polyvinyl chloride (PVC); andfluorinated polymers such as polytetrafluoroethylene (PTFE). Polymerscan be crystalline, semi-crystalline or amorphous.Filler additions: metals (Ag, Al, In, Mg, Si, Sn, Pt, Ti, V, W, Zn);metal oxides (Ag₂O, Al₂O₃, SiO₂, SnO₂, TiO₂, ZnO); carbides of B, Cr,Bi, Si, W; carbon (carbon, carbon fibers, carbon nanotubes, diamond,graphite, graphite fibers); glass; glass fibers; fiberglass metallizedfibers such as metal coated glass fibers; mineral/ceramic fillers suchas talc, calcium silicate, silica, calcium carbonate, alumina, titaniumdioxide, ferrite, mica and mixed silicates (e.g. bentonite or pumice).Minimum particulate/fiber fraction [% by volume]: 0; 1; 5; 10Maximum particulate/fiber fraction [% by volume]: 50; 75; 95

Metallic Coating/Metallic Layer Specification:

Minimum coefficient of linear thermal expansion [10⁻⁶ K⁻¹]: −5.0; −1.0;0Maximum coefficient of linear thermal expansion [10⁻⁶ K⁻¹]: 15; 20; 25Microstructure: Amorphous or crystallineMinimum average grain size [nm]: 2; 5; 10Maximum average grain size [nm]: 100; 500; 1,000; 5,000; 10,000Metallic layer Thickness Minimum [μm]: 2.5, 10; 12.5, 25; 30; 50; 100Metallic layer Thickness Maximum [mm]: 5; 25; 50Metallic materials comprising at least one of: Ag, Al, Au, Co, Cr, Cu,Fe, Ni, Mo, Pb, Pd, Pt, Rh, Ru, Sn, Ti, W, Zn and ZrOther alloying additions: B, C, H, O, P and SParticulate additions: metals (Ag, Al, In, Mg, Si, Sn, Pt, Ti, V, W,Zn); metal oxides (Ag₂O, Al₂O₃, SiO₂, SnO₂, TiO₂, ZnO); carbides of B,Cr, Bi, Si, W; carbon (carbon nanotubes, diamond, graphite, graphitefibers); glass; polymer materials (PTFE, PVC, PE, PP, ABS, epoxy resins)Minimum particulate fraction [% by volume]: 0; 1; 5; 10Maximum particulate fraction [% by volume]: 50; 75; 95

Minimum Yield Strength Range [MPa]: 300 Maximum Yield Strength Range[MPa]: 2,750 Minimum Hardness [VHN]: 100; 200; 400 Maximum Hardness[VHN]: 800; 1,000; 2,000

Minimum Deposition Rates [mm/hr]: 0.01; 0.05; 0.1; 0.2; 0.5

Intermediate Layer Specification:

Metallic Layer: composition selected from metallic materials list setforth above, including electroless Ni, Cu, Co and/or Ag comprisingcoatings; metallic layers can contain an oxide layer on the outersurface, which can promote the bond strength to the polymer substrate.Oxide layer: oxides of elements as listed in the metallic materialslist, including Ni, Cu, Ag oxidesPolymeric Layer: composition selected from polymeric materials listincluding partly cured layers prior to coating and finishing heattreatment, also cured polymeric paint (carbon, graphite, Ni, Co, Cu, Agfilled curable polymers, adhesive layer).

Intermediate Layer Thickness Minimum [μm]: 0.005; 0.025; IntermediateLayer Thickness Maximum [μm]: 1; 5; 25; 50 Interface Specification(Polymer/Intermediate Layer Interface or Polymer/Metallic LayerInterface):

Minimum surface roughness Ra, Ry, Ry_(max), Rz [μm]: 0.01; 0.02; 0.05;0.1; 1Maximum surface roughness Ra, Ry, Ry_(max), Rz [μm]: 25; 50; 500; 5,000Minimum linear population of anchoring surface structures [number percm]: 10; 100; 1,000Maximum linear population of anchoring surface structures [number percm]: 10⁵; 10⁶; 10⁷Minimum areal population of anchoring surface structures [number permm²]: 1, 100; 10⁴Maximum areal population of anchoring surface structures [number permm²]: 10⁷; 10¹⁰Minimum anchoring structure diameter [nm]: 10, 50, 100Maximum anchoring structure diameter [μm]: 500; 1,000Minimum anchoring structure height/depth [nm]: 10, 50, 100Maximum anchoring structure height/depth [μm]: 500; 1,000Anchoring surface structure topography: recesses; protrusions;“inkbottle type” cavities; pitted anchoring surface structures; holes;pores; depressions; anchoring surfaces with protruding anchoring fibers;grooved, roughened and etched anchoring surface structures; nodules;dimples; mounds; as well as honeycomb or open foam type structures;“brain”, “cauliflower”, “worm”, “coral” and other three dimensionallyinterconnected porous surface structures. Typically any number ofdifferent anchoring structures is present in the suitably texturedsurface, their shapes and areal densities can be irregular and the clearidentification of individual anchoring structures can be subject tointerpretation. The most reliable method therefore to account for theeffect of anchoring structures is to measure the adhesion property ofthe metal-clad polymer article, e.g., using the ASTM D4541-02 pull-offstrength test.

Metal-Clad Polymer Article Specification: Adhesion:

Minimum pull-off strength of the coating according to ASTM D4541-02Method A-E [psi]: 200; 300; 400; 600Maximum pull-off strength of the coating according to ASTM D4541-02Method A-E [psi]: 2,500; 3,000; 6,000

Thermal Cycling Performance:

Minimum thermal cycling performance according to ASTM B553-71: 1 cycleaccording to service condition 1 without failure (no blistering,delamination or <2% displacement) and with <2% displacement between thepolymer and metallic material layers.Maximum thermal cycling performance according to ASTM B553-71: infinitenumber of cycles according to service condition 4 without failure.

Metal-Clad Polymer Article Mechanical Properties:

Polymer substrate weight fraction of the metal-clad polymer article [%]:5 to 95Minimum yield strength of the metal-clad polymer article [MPa]: 5; 10;25; 100Maximum yield strength of the metal-clad polymer article [MPa]: 5,000;7,500.Minimum ultimate tensile strength of the metal-clad polymer article[MPa]: 5; 25; 100Maximum ultimate tensile strength of the metal-clad polymer article[MPa]: 5,000; 7,500Minimum elastic limit of the metal-clad polymer article [%]: 0.5; 1Maximum elastic limit of the metal-clad polymer article [%]: 5; 10, 30

The following description summarizes the test protocols used:

Adhesion Test Specification:

ASTM D4541-02 “Standard Test Method for Pull-Off Strength of CoatingsUsing Portable Adhesion Testers” is a test for evaluating the pull-offstrength of a coating on rigid substrates determining the greatestperpendicular force (in tension) that a coating/substrate interfacesurface area can bear before it detaches either by cohesive or adhesivefailure. This test method maximizes tensile stress as compared to shearstress applied by other methods, such as scratch or knife adhesion andthe results may not be comparable. ASTM D4541-02 specifies fiveinstrument types identified as test Methods A-E and the pull offstrength reported is an average of at least three individualmeasurements.

Thermal Cycling Test Specification:

ANSI/ASTM specification B604-75 section 5.4 Test (Standard RecommendedPractice for Thermal Cycling Test for Evaluation of ElectroplatedPlastics ASTM B553-71). In this test the samples are subjected to athermal cycle procedure as indicated in Table 1. In each cycle thesample is held at the high temperature for an hour, cooled to roomtemperature and held at room temperature for an hour and subsequentlycooled to the low temperature limit and maintained there for an hour.

TABLE 1 Standard Recommended Practice for Thermal Cycling Test forEvaluation of Electroplated Plastics According to ASTM B553-71 ServiceCondition High Limit [° C.] Low Limit [° C.] 1 (mild) 60 −30 2(moderate) 75 −30 3 (severe) 85 −30 4 (very severe) 85 −40

If any blistering, delamination or cracking is noted the test isimmediately suspended. After 10 such test cycles the sample is allowedto cool to room temperature, is carefully checked for delamination,blistering and cracking and the total displacement of the coatingrelative to the substrate is determined.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a picture of the top and bottom of a fullyencapsulated coupon according to the invention illustrating the massivedeformation of the metal-clad polymer article which occurred during thepull test without any delamination between the embossed and etchedpolymer and the metal layers.

DETAILED DESCRIPTION

This invention relates to laminate articles comprising structuralmetallic material layers on polymeric substrates that are suitablyshaped to form a precursor of the metal-clad polymer article. Themetallic materials/coatings are fine-grained and/or amorphous and areproduced by DC or pulse electrodeposition, electroless deposition,physical vapor deposition (PVD), chemical vapor deposition (CVD) and gascondensation or the like. Debonding of the coating from the substratedue to the intrinsic mismatch of the coefficient of thermal expansion ofthe metal and the polymer of the inventive metal-clad polymer articlesis overcome and acceptable thermal cycling performance achieved byenhancing the pull-off strength between the metallic material and thepolymer by suitable surface activation and/or surface roughness and/ormetal-polymer interface surface design.

The person skilled in the art of plating will know how to electroplateor electroless plate selected fine-grained and/or amorphous metals,alloys or metal matrix composites choosing suitable plating bathformulations and plating conditions. Similarly, the person skilled inthe art of PVD, CVD and gas condensation techniques will know how toprepare fine-grained and/or amorphous metal, alloy or metal matrixcomposite coatings.

Applying metallic coatings to polymer and polymer composite parts is inwidespread use in consumer and sporting goods, automotive and aerospaceapplications. Polymer composites with carbon/graphite and/or glassfibers are relatively inexpensive, easy to fabricate and machine;however, they are not very durable. Metallic coatings are thereforefrequently applied to polymers and polymer composites to achieve therequired mechanical strength, wear and erosion resistance and to obtainthe desired durability and service life. To achieve the requireddurability of laminate articles excellent bond strength between themetallic layer and the polymer substrate is of paramount importance.

A variety of fine-grained and/or amorphous metallic coatings, which atroom temperature have a coefficient of thermal expansion in the rangebetween minus 5.0×10⁻⁶ K⁻¹ and 25×10⁻⁶ K⁻¹ in all directions, can beemployed. Particularly suited are fine-grained and/or amorphoushigh-strength pure metals or alloys containing Ag, Al, Au, Co, Cr, Cu,Fe, Ni, Mo, Pb, Pd, Pt, Rh, Ru, Sn, Ti, W, Zn and Zr; and optionally oneor more elements selected from the group consisting of B, C, H, O, P andS; and/or optionally containing particulate additions such as metalpowders, metal alloy powders and metal oxide powders of Ag, Al, Au, Cu,Co, Cr, Fe, Ni, Mo, Pd, Pt, Sn, Rh, Ru, Ti, W, Zn and Zr; nitrides ofAl, B and Si; C (graphite, carbon fibers, carbon nanotubes or diamond);carbides of B, Cr, Bi, Si, W; ceramics, glasses and polymer materialssuch as polytetrafluoroethylene (PTFE), polyvinylchloride (PVC),acrylonitrile-butadiene-styrene (ABS), polyethylene (PE), polypropylene(PP). The particulate average particle size is typically between 500 nmand 5 μm.

Metallic coatings can have a coarse-grained, fine-grained or amorphousmicrostructure. One or more metallic coating layers of a single orseveral chemistries and microstructures can be employed. The metalliccoating can be suitably exposed to a finishing treatment, which caninclude, among others, electroplating, i.e., chromium plating andapplying a polymeric material, i.e., paint or adhesive.

Polymeric substrates, for the most part have a CLTE significantlyexceeding 25×10⁻⁶ K⁻¹ in at least one direction. Selected polymericmaterials and particularly filled or reinforced polymeric materials, candisplay coefficient of thermal expansion values which are not isotropic,but vary significantly with the direction. As an example, glass filledpolyamide can have coefficient of linear thermal expansion (CLTE) valuesas low 20-75×10⁻⁶ K⁻¹ in one direction and as high as 100-250×10⁻⁶ K⁻¹in another direction. In the case of fiber reinforced polymer materials,as fibers usually align in the plane of the part during molding, theCLTE of the polymer in the plane is typically lower than the CLTEperpendicular/normal to it. The degree of CLTE match or CLTE mismatchbetween the coating and the substrate and the bond strength between thecoating and the substrate play an important role in preventingdelamination and affecting the relative coating/substrate displacementin industrial composite parts exposed to thermal cycling. To clarify,the stronger the bond strength between the polymer and the metallicmaterial the more CLTE mismatch and the higher the temperaturefluctuations the metal-clad polymer article can endure. It is thereforeof crucial importance to suitably roughen/pretreat/activate thepolymeric surface to ensure the bond strength to the coatings andparticularly metallic coatings is optimized. Of course, mechanicalproperties of the substrate and coating are important as well,particularly the yield strength, ultimate tensile strength, resilienceand elongation. As known in the case of glass filled polymers the use ofammonium fluoride containing etchants has shown to enhance adhesion.

Suitable polymeric substrates include crystalline, semi-crystallineand/or amorphous resins as well as unfilled or filled resins. Suitablepolymeric substrates include epoxy, phenolic and melamine resins,polyester resins, urea resins; thermoplastic polymers such asthermoplastic polyolefins (TPOs) including polyethylene (PE) andpolypropylene (PP); polyamides, including aliphatic and aromaticpolyamides, mineral filled polyamide resin composites; polyphthalamides;polyphthalates, polystyrene, polysulfone, polyimides; neoprenes;polybutadienes; polyisoprenes; butadiene-styrene copolymers;poly-ether-ether-ketone (PEEK); polycarbonates; polyesters; liquidcrystal polymers such as partially crystalline aromatic polyesters basedon p-hydroxybenzoic acid and related monomers; polycarbonates;acrylonitrile-butadiene-styrene (ABS); chlorinated polymers suchpolyvinyl chloride (PVC); and fluorinated polymers such aspolytetrafluoroethylene (PTFE). Useful thermoplastic resins includepoly(oxymethylene) and its copolymers; polyesters such as poly (ethyleneterephthalate), poly (1,4-butylene terephthalate), poly(1,4-cyclohexyldimethylene terephthalate), andpoly(1,3-propyleneterephthalate); polyamides such as nylon-6,6, nylon-6,nylon-12, nylon-11, nylon-10,10, and aromatic-aliphatic copolyamides;polyolefins such as polyethylene (i.e. all forms such as low density,linear low density, high density, etc.), polypropylene, polystyrene,polystyrene/poly (phenylene oxide) blends, polycarbonates such as poly(bisphenol-A carbonate); fluoropolymers including perfluoropolymers andpartially fluorinated polymers such as copolymers of tetrafluoroethyleneand hexafluoropropylene, poly (vinyl fluoride), and the copolymers ofethylene and vinylidene fluoride or vinyl fluoride; poly-sulfides suchas poly (p-phenylenesulfide); polyetherketones such as poly(ether-ketones), poly (ether-ether-ketones), and poly(ether-ketone-ketones); poly (etherimides);acrylonitrile-1,3-butadinene-styrene copolymers; thermoplastic (meth)acrylic polymers such as poly (methyl methacrylate); and chlorinatedpolymers such as poly (vinyl chloride), polyimides, polyamideimides,vinyl chloride copolymer, and poly (vinylidene chloride). Useful“thermotropie liquid crystalline polymer” (LCP) include polyesters, poly(ester-amides), and poly (ester-imides). One preferred form of polymeris “all aromatic”, that is all of the groups in the polymer main chainare aromatic (except for the linking groups such as ester groups), butside groups which are not aromatic may be present. The thermoplasticsmay be formed into parts by the usual methods, such as injectionmolding, thermoforming, compression molding, extrusion, and the like.

These polymeric substrates frequently contain fillers including carbon,carbon nanotubes, graphite, graphite fibers, carbon fibers, metals,metal alloys, glass and glass fibers; fiberglass, metallized fibers suchas metal coated glass fibers; pigments, dyes, stabilizers, tougheningagents, nucleating agents, antioxidants, flame retardants, process aids,and adhesion promoters and the like. Appropriate filler additions in thesubstrate range from as low as 2.5% per volume or weight to as high as95% per volume or weight. In addition to fibrous reinforcing fillerswith a high aspect ratio, other fillers such as glass, ceramics andmineral fillers such as talc, calcium silicate, silica, calciumcarbonate, alumina, titanium dioxide, ferrite, and mixed silicates (e.g.bentonite or pumice) can be employed as well.

Particularly suitable substrates include carbon/graphite fiber and glassfiber resin composites in which the resin components include phenolicresins, epoxy resins, polyester resins, urea resins, melamine resins,polyimide resins, polyamide resins as well as elastomers such as naturalrubber, polybutadienes, polyisoprenes, butadiene-styrene copolymers,polyurethanes, and thermoplastics such as polyethylene, polypropylene,and the like.

During molding/shaping of the precursor metal-clad article, polymerchains do not necessarily align themselves in a random manner but ratherdisplay directionality depending on part geometry, molding conditions,material flow patterns etc. Similarly, fiber additions usually align inthe plane and the electrical and thermal conductivities of suchcomposites in a plane can be 10-100 times higher than perpendicular tothe plane. Therefore, directional properties need to be considered inmetal-clad polymer articles. Furthermore, non uniformity of the moldedpolymer or polymer matrix composite substrates can at times beexacerbated near the surface and significant differences in compositionand properties near the outer surface layer, which participates informing the bond to a coating layer and the interior bulk of the moldedpolymer, can exist.

To enhance the bond between the metallic layer, i.e., themetalizing/intermediate layer or the fine-grained/amorphous metalliclayer and the polymer, polymeric surfaces forming the interface with themetallic layer are typically preconditioned before the metallic layersare applied. Numerous attempts have been made to identify, characterizeand quantify desired surface features which result in achieving thedesired bonding properties and to quantify the surface topography andsurface roughness in quantifiable scientific terms. Heretofore, theseefforts have not succeeded in part because of the complexity of thesurface features, the numerous parameters such as population, size andshape of the anchoring structures which affect the mechanicalinterlocking. Furthermore, it is not even clear if the bond strengthbetween metals and polymers is entirely dictated by mechanical forces orif chemical interactions, e.g., between functional surface groups of thepolymers present or introduced during etching, contribute to the bondstrengths as typically after etching the contact angle is reduced due tothe creation of hydrophilic functional groups, i.e., —COOH and —COH.Similarly, the metal surface at the interface can be at least partiallyoxidized which at times can enhance the adhesion.

Anchoring structures are surface features induced on the polymericsurface by the various surface preconditioning methods used including,but not limited to, mechanical abrasion, swelling, dissolution, chemicaletching and plasma etching, and furthermore depend on the composition ofthe polymer substrate and the amount, size and shape of fillersemployed. In practice when dealing with polymeric and metallic surfacesthat are pretreated to improve adhesion, surface features are usuallyquite irregular and difficult to describe/measure in absolute terms andattempts to quantify surface features responsible for good adhesionbetween the coating and the substrate have not been successful to date.Alternatively, as outlined in another preferred embodiment the polymercan be applied to a suitably rough metal substrate.

Over time a variety of standardized tests measuring adhesion have beendeveloped and results from one test are frequently not comparable withresults obtained with another test. The most popular test for adhesionbetween the metallic coating and a polymer substrate are peel tests. Theforce measured to peel a thin coating off the substrate relates to aforce required to propagate debonding and before the test is initiatedthe coating is purposely debonded from the substrate. Peel tests measurethe interfacial fracture energy and are used to characterize adhesiveand thin metal coatings (decorative coatings) up to a thickness of 20microns. When the thickness and the strength of the coatings increase,e.g., in the case of thick structural coatings/layers employingfine-grained metallic coatings, peel tests do not provide meaningfulresults. Pull-off tests, on the other hand, measure the force requiredto debond a unit area of the interface of the substrate and the coatingand, in the case of metal-clad polymer articles with structural metalliclayers, they are more relevant as the objective is to increase the forcerequired for initiation of debonding as much as possible. In contrast topeel tests, pull-off test results are unaffected by the coatingthickness. As illustrated in selected examples below there is noreliable correlation between pull-off and peel strength data.

Ways are sought to enable tolerating a larger CLTE mismatch between ametallic coating/layer and polymeric materials/substrates employed instrong, lightweight and structural laminate/metal-clad polymer articlesas the bond strength achieved remains significantly below the oneachieved between metallic coatings and metallic substrates. As theappropriate surface preparation of the substrate is known to have asignificant impact on the bond strength and adhesion, the preferredapproach is to provide means of substantially enhancing the bondstrength between the metallic layer and the polymer. As highlighted, thesurface topography created during the pretreatment procedure has asignificant effect on adhesion. Ideally, when employing surfacepretreatment methods, anchoring structures selected from the group of“inkbottle type” cavities, pitted anchoring surface structures, nodules,anchoring surfaces with protruding anchoring fibers, grooved, roughenedand etched anchoring surface structures are formed at the interfacebetween the metallic layer and the polymeric substrates and interlockthe metallic and polymer layers raising the adhesion strength. Thenumber, population density, shape, size and depth of anchoringstructures greatly affects the bond strength achievable and thereforestandardized adhesion tests are required to determine and objectivelycompare bond quality such as ASTM D4541-02.

Platable polymeric compositions therefore frequently employ “removablefillers” which are extracted from the near surface of the metal-polymerinterface by a suitable pretreatment prior to metal deposition. In thecase of polymer composites containing “permanent fibers” pretreatmentmethods and conditions can be optimized to “expose” some of the embeddedfibers to enable the coating to adhere thereto and, at least partiallyencapsulate them, again resulting in enhanced bond strength and in anincrease in CLTE mismatch between the coating and the substrate that canbe tolerated. Many suitable polymeric compositions therefore containboth removable and permanent fillers. Leaching of the removable fillersalone without the creation of additional anchoring structures has beendetermined not to create a sufficiently high population of anchoringstructures to meet the pull-off strength requirement of the metal-cladpolymer article.

Desired metallic material-polymeric material interface surface featurescan be generated in a shaped polymer precursor article or a metalliclayer in several ways:

1. Mechanical Surface Roughening of the Polymer and/or Metal Interface:

The surface of the substrate to be coated can be suitably roughened by amechanical process, e.g., by sanding, grid blasting, grinding and/ormachining.

2. Imprinting of the Polymer Surface by Molding and/or Other ShapingMethods:

Desirable anchoring structures can be imprinted/patterned on the surfaceof the substrate to be coated by suitable polymer molding, stamping,forming and/or shaping methods, all applying pressure to the soft,softened or molten polymer surface, including but not limited toinjection, compression and/or blow molding, and “print rolling”. Allpolymer forming and shaping processes can be, in principle, adapted toimpart or transfer the desired surface texture to the polymer substratesurface.

A particularly elegant way of creating the desired surface features inpolymers in a reproducible manner involves embossing the polymer surfacewith a suitable die as described in co-pending application Integran 6238by J. J. Victor entitled “Articles with Super-Hydrophobic and/orSelf-Cleaning Surfaces and Methods of Making Same”. A suitable processfor producing suitable nanostructured and microstructured depressions ina mold entails, e.g., placing suitable metallic embossing inserts intothe mold or coating the mold surface itself. The microstructure of thesemetallic embossing dies is preferably amorphous or fine-grained, whichwas found to provide superior properties than the use of conventionalcoarse-grained metallic materials. The embossing dies preferablycomprise at least one element selected from the group consisting of Ni,Co and Fe. To generate the embossing topography these amorphous orfine-grained metal surfaces are preferably shot peened and/or etched tocreate the desired surface feature die. Shot peening followed by etchinghas been found to create particularly desirable features. These surfacefeatures are transferred onto the polymer surface by embossing byapplication of pressure and/or heat preferably above the softeningtemperature for the polymer. In addition to substantially enhancing theadhesion strength between the polymer substrate and the applied coating,these processes have also been found to increase the contact angle forwater and can be used to render the treated surface superhydrophobic andself-cleaning.

3. Chemical Etching of the Polymer and/or Metal Interface Near-Surface:

Chemical etching using oxidizing chemicals such as mineral acids, basesand/or oxidizing compounds such as permanganates is the most popularmethod for etching polymers practiced in industry. This method alsobenefits from the use of “platable polymer grades” which contain fillermaterials which, in the near outer surface layer, are dissolved duringthe etching process.

The co-pending application by McCrea entitled “Anodically AssistedChemical Etching of Conductive Polymers and Polymer Composites” (U.S.Ser. No. 12/476,506) discloses a surface activation process forconductive polymers/polymer composites consisting of simultaneouslyapplying anodic polarization and chemical etching, referred to as“anodically-assisted chemical-etching” or “anodic assisted etching”.This process drastically enhances the bond strength between theactivated substrate and the applied coating. Simultaneous chemical andelectrochemical etching of polymeric substrates substantially enhancesthe bond, peel and shear strength between the polymeric substrate andthe applied metallic coating/layer as highlighted in the co-pendingapplication.

Solvent free chemical etching can be employed as well, to etch and/orsuitably texture the outer surface including plasma etching or etchingwith reactive gases including, but not limited to, SO₃ and O₃, tosuitably precondition and texture the surface. Special additives canfurther enhance adhesion, i.e., in the case of glass filled polymers theuse of fluoride-ions containing etchants greatly enhances adhesion.

4. Swelling of the Polymeric Substrate Surface:

Application of swelling agents to create anchoring structures in thenear surface of the polymer with or without the use of etching andabrasion methods can be employed. Suitable swelling agents includeorganic solvents for one or more polymers in the substrate including,but not limited to alcohols such as glycols.

5. Applying Adhesive Layers or Partially Cured Polymeric Substrates:

Where applicable, partly cured polymer substrates may be activated andcoated, followed by an optional curing heat treatment. Similarly,adhesive layers may be applied between the polymeric substrate and themetallic coating which can also be followed by an optional curing heat.

6. Post Cure Treatment of Metal-Clad Polymer Articles:

Another process that can be used to improve the adhesion between thepolymeric substrate and the metallic layer entails a suitable heattreatment of the metal-clad article for between 5 minutes and 50 hoursat between 50 and 400° C.

7. Applying the Polymer to a Rough Metal Surface:

Another approach entails first forming the metallic layer with onesurface to be covered by the polymer purposely “roughened” andcontaining suitable surface features/protrusions/surface roughness tocreate anchoring structures elevating from the metallic surface,recessing into the metal surface or their combinations, to aid inenhancing the adhesion to the polymeric substrate. In this case thepolymeric material is applied onto the metallic material and notvice-versa.

Combinations of two or more of the aforementioned processes can be usedas well and the specific pretreatment conditions typically need to beoptimized for each polymer and molded part to generate a sufficientlyhigh number of anchoring structures to maximize the bond strength whichcan be conveniently determined using the pull off test described.

To illustrate the incredible, heretofore unachieved, bond strengthbetween polymers and metals possible according to this invention FIG. 1illustrates samples which underwent the ASTM D4541-02 “Standard TestMethod for Pull-Off Strength of Coatings Using Portable AdhesionTesters” without any delamination or loss of adhesion between themetal(s) and the polymer. This test involves attaching a pull stub(dolly) to the flat face of the metallic coating using an adhesive.After suitable curing the coating around the dolly is cut all the way tothe substrate. After preparation the assembly is transferred to ameasuring device in which a coupling connector locks on to the dolly,and a pressure source applies an increasing normal force on the dolly.When the pressure on the dolly is greater than the bond strength betweenthe coating and the substrate, separation occurs and the connector-dollyassembly lifts the coating from the substrate. A pressure gage recordsthe pressure at separation, which is the reported pull-off strength inpsi. As FIG. 1 indicates selected samples, particularly samples whichwere embossed and etched, exhibit such a high adhesion strength betweenthe polymer and the metallic layers that the metal coating and polymerseverely deform and lift out of the sample plane without failure or anysigns of delamination of the polymer-metal interface, i.e., the pull-offstrength could not be determined according to ASTM D4541-02.Specifically to FIG. 1, the picture on the left depicts the view fromthe bottom of metal-clad glass-filled polyamide sample (embossed, etchedin sulfochromic acid with glycol and F′) after a pull-off test, clearlyindicating the severe deformation (cupping) that occurred during thepull off test. The picture on the right displays the top view with themetal-clad filled polypropylene sample (embossed, etched in sulfochromicacid) and the pull stub or dolly still attached indicating that thebottom of the pulls tub or dolly and the adjacent metal-clad polymerlayer significantly lifted out of the original base plane, again withoutany signs of delamination at the metal/polymer interface.

As highlighted, carbon-fiber and/or graphite-fiber and/or glass-fiber(referred to as carbon/graphite/glass-fiber) polymer composite molds arepopular for sporting goods, automotive and aerospace parts and forfabricating composite prototypes for the aerospace industry.Carbon/graphite/glass-fiber polymer composite molds are inexpensive butlack durability and therefore find use only for prototyping. Depositing,e.g., fine-grained and/or amorphous metals such as Ni, Co, Cu and/orFe-based alloys onto the carbon/graphite-fiber polymer composite moldsprovides for tremendous cost savings over the traditional approach ofmachining and forming Invar molds.

Similarly, carbon/graphite-fiber polymer composites are also a popularchoice for aerospace components including plane fuselage, wings, rotors,propellers and their components as well as other external structuresthat are prone to erosion by the elements including wind, rain, hail andsnow or can be damaged with impact by debris, stones, birds and thelike. Aerospace and defense applications particularly benefit from astrong, tough, hard, erosion-resistant fine-grained and/or amorphouscoating. Lightweight laminate articles are also employed in internalairplane parts.

Suitable laminate metallic-material/polymeric-material articles include,but are not limited to, precision graphite fiber/epoxy molds used inaerospace, automotive and other industrial applications that are exposedto repeated temperature cycling (between −75° C. and up to 350° C.).Metal-clad polymer parts made from the fine-grained and/or amorphousmetallic coatings on appropriate substrates are well suited for highprecision molding components requiring great dimensional stability overa wide operating temperature range.

In applications where coatings are applied to substrates it has beendesired for the coefficient of linear thermal expansion (CLTE) of, e.g.,the metal coating to be closely matched to the CLTE of the polymericsubstrate or polymer composite to avoid delamination/failure duringthermal cycling. Similarly in molding applications (blow, injection,compression molding and the like) good matching of the thermal expansionproperties of all components is conventionally required to avoidspring-back and delamination during the heating and the cooling cycle.The tolerable “CLTE mismatch” between the metallic layer and the polymerdepends on the application, the quality of the adhesion between thecoating and the polymer substrate, the maximum and minimum operatingtemperature and the number of temperature cycles the article is requiredto withstand in its operating life. In all instances, after apredetermined number of thermal cycles, consisting either of submersingthe article in liquid nitrogen for one minute followed by submersion inhot water for one minute, or other suitable thermal cycling testsincluding ANSI/ASTM specification B604-75 section 5.4 Test (StandardRecommended Practice for Thermal Cycling Test for Evaluation ofElectroplated Plastics ASTM 13553-71), the coating relative to theunderlying substrate should not fail. Delamination, blistering orcracking of the coating and/or the substrate which would compromise theappearance or performance of the article are all considered failure.Similarly, a displacement of the coating relative to the underlyingsubstrate of more than 2% constitutes failure.

Suitable permanent substrates include polymeric materials filled with orreinforced with e.g. graphite or glass which reduces the CLTE in atleast the plane of the polymeric substrate. For added strength,durability and high temperature performance filled polymers are verydesirable. The term “filled” as used herein refers to polymer resinswhich contain fillers embedded in the polymer, e.g., fibers made ofgraphite, carbon nanotubes, glass and metals; powdered mineral fillers(i.e., average particle size 0.2-20 microns) such as talc, calciumsilicate, silica, calcium carbonate, alumina, titanium oxide, ferrite,and mixed silicates. A large variety of filled polymers having a fillercontent of up to about 95% by weight are commercially available from avariety of sources. If required, e.g., in the case of electricallynon-conductive or poorly conductive substrates and the use ofelectroplating for the coating deposition, the substrates can bemetallized to render them sufficiently conductive for plating.

As highlighted, a number of processes can be used to form the metal-cladpolymer articles. In the case of using electroplating to apply themetallic layer to the polymer substrate, the polymer substrate, aftersuitably being appropriately shaped and activated, is preferablymetallized to enhance the surface conductivity typically by applying athin layer called the “intermediate conductive layer” or “metalizinglayer”. The intermediate conductive layer can comprise a metallic layeror can comprise polymeric material with conductive particulates therein.Where the intermediate conductive layer comprises a metallic layer, themetallic layer is constituted of Ag, Ni, Co or Cu or a combination ofany two or all of these, and the intermediate conductive layer can bedeposited by electroless deposition, sputtering, thermal spraying,chemical vapor deposition, physical vapor deposition of by any two ormore of these. Where the intermediate conductive layer comprisespolymeric material with conductive particulates therein, it can be, forexample, a conductive paint or a conductive epoxy. The conductiveparticulates can be composed of or contain Ag, Ni, Co or Cu or graphiteor other conductive carbon or a combination of two or more of these. Ashighlighted the surface of the metal layer or metal particulates can beoxidized to enhance adhesion.

As highlighted, the metal-clad polymer articles comprising thefine-grained and/or amorphous metal coatings, provide for lightweightparts exhibiting high strength, rigidity and impact performance fornumerous applications and/or provide for further desired functionalproperties. In the case of electrical or electronic components orhousings, the metal layer or preferably multi-compositional conformalmetal layers can be designed and placed on selected sections or theentire part to enhance the thermal conductivity and improve heatdissipation from heat sources such as batteries or electroniccomponents. Cu, Ag, Au and their alloys are known to have excellentthermal conductivity. The thermal conductivity can be further enhancedby particulate additions, particularly diamond. Such metal, metal alloy,or metal matrix composite layers can conveniently be formed on thesubstrate or an intermediate conductive layer by electroless,electrodeposition and/or spraying processes. Furthermore, conformalelectromagnetic interference (EMI) and/or radio frequency interference(RFI) shielding layer or layers comprising metals or alloys selectedfrom the group consisting of Ni, Co and Fe can be applied by variousdeposition techniques including electroplating.

Regarding heat dissipation, polymeric materials (ABS, nylonpolypropylene) have thermal conductivities 200-4,000 times lower thanpopular metals such as Al, Ag, Cu, Ni, steel and NiFe alloys and heatdissipation can become a significant issue resulting in malfunctioncaused by overheating. Encapsulation of the polymer part or housing byor applying selective metallic patches strategically near areas of heatgeneration (battery, electronic circuit) with metallic materials,preferably comprising at least one element selected from the groupconsisting of Ag, Cu, Co, Ni, Fe, Sn and Zn and thermal conductivitiesexceeding 10 W/(m·K), preferably exceeding 100 W/(m·K) and up to 2,500W/(m·K), optionally containing particulates of high thermal conductivitysuch as diamond [thermal conductivities>900 W/(m·K)], preferably to atotal thickness of at least 12.5 microns and more preferably of at least25 microns, are desired. A single layer or multiple layers offine-grained or amorphous Cu and its alloys including Cu—Sn (bronze) andCu—Zn (brass), optionally containing diamond particulates ranging from 1to 50% per volume, which can be applied to the inside and/or outside ofsuitable polymer substrates, an intermediate metallic layer, or afine-grained or an amorphous metallic layer by electroless deposition orelectrodeposition, are particularly suitable to enhanceheat-dissipation.

Similarly, electromagnetic interference (EMI) shielding and radiofrequency interference (RFI) shielding can be significantly enhancedwhen suitable fine-grained or amorphous metallic materials comprising atleast one element selected from the group consisting of Ni, Co, Cu, Fe,Mo, W, Zn, P, B, and C are applied directly to the inside and/or outsideof electrical and electronic covers and housing. Suitable conformalmetallic coatings preferably comprise Fe alloyed with Co and/or Ni,having a minimum Fe content of 5% and a minimum content of Ni and/or Cotogether of 2.5%. Additional metallic layers can be added, i.e., fordecorative purposes and to enhance the wear performance, such as Cr.Paints or other synthetic coatings can be applied as well.

To achieve antimicrobial properties preferably the outer metallic layerconsists of an amorphous or fine-grained metallic coating comprising atleast one metal selected from the group consisting of comprising Ag, Co,Cu and Ni.

For a number of applications including, but not limited to, appearance,ease of gripping/holding or antimicrobial use, it is desirable that theouter metal surface is not perfectly smooth, but rough. This can beachieved either by post-treatment of the metal surface using amechanical or chemical roughening process or care is taken that part ofthe polymer surface structures of the substrate are retained in theouter surface of the metallic coating by avoiding leveling/filling ofthe recesses. Such desirable satin metal finishes have a surfaceroughness of Ra between ≧0.5 microns and ≦50 microns.

The following working examples illustrate the benefits of the invention,specifically a comparison of pull-off and peel strength data for twosets of metal-clad polymer samples processed the same way, namely ABSpolymeric substrate coated with an organic adhesive layer that ispartially cured, then coated with a Ag intermediate layer and afine-grained Ni—Fe layer, followed by heat treatment to fully cure thepart (Working Example I); mechanically abraded graphite-fiber epoxysubstrates coated with fine-grained nickel (Working Example II);chemically and anodically etched carbon fiber cloth reinforcedbismaleimide substrates, then coated with a Ag intermediate layer andcoated with a fine-grained nickel-iron alloy (Working Example III);chemically etched graphite-fiber and glass fiber reinforced polymersubstrates coated with nickel-based materials with an amorphous orfine-grained microstructure using an intermediate conductive Ag layer(Working Example IV); coating of fully-cured and partially-curedgraphite reinforced polymer composites with a silver (Ag) intermediatelayer and a fine-grained Ni layer, including heat treatment of thepartially-cured coated part (Working Example V); coating of a chemicallyetched glass fiber reinforced polyamide polymer composite with a Ni—Pintermediate layer with a fine-grained Ni metal layer, followed by apost-plating heat-treatment (Working Example VI); and a polypropylenebacking layer applied to a fine-grained Co—P metal layer with a roughinterface surface produced electrochemically (Working Example VII);coating of a molded embossed polypropylene cell phone casings, followedby chemical etching, metalized with a Ni—P intermediate layer andelectroplated with a fine-grained Cu layer and a fine-grained Ni—Co—Femetal layer (Working Example VIII); coating of a molded embossedpolyamide cell phone casings, followed by chemical etching, metalizedwith a Cu intermediate layer and electroplated with a fine-grained Culayer, a fine-grained Ni—Fe metal layer, and a number of top coat layers(Working Example IX); and coating of a molded polyamide or polypropyleneparts without and with compression molding embossing, followed bychemical etching, metalized with a Ni—P intermediate layer andelectroplated with a fine-grained Ni layer (Working Example X);Intermediate metalizing layers were used in Working Examples I, III, IV,V, VI and VIII, IX and X.

The invention is illustrated by the following working examples.

Working Example I Comparison of Pull-Off and Peel Strength for HighDensity ABS Substrate Coated with an Adhesive Layer, then Metallizedwith an Ag Intermediate Layer and a Fine-Grained Ni—Fe Layer with andwithout Heat Treatment of the Coated Part

Two 10×15 cm coupons were cut from a commercial 6 mm ABS sheet (CLTE:˜75×10⁻⁶ K⁻¹ in all directions) The coupons were ground on one side with80 grit SiC paper to a consistent surface roughness. The samples werethen cleaned with Alconox and steel wool, followed by ultrasonicallycleaning in deionized water for 5 minutes. The samples were rinsed inisopropanol, dried and degreased with 1,2-dichloroethane to remove anyresidual oils and/or films.

Subsequently, the coupons were coated on one side with a thin film of acommercial epoxy-based adhesive available from Henkel Canada, Brampton,Ontario (LePage 11). The epoxy based adhesive coating was then partiallycured at room temperature for 2 hours. Thereafter the panels werechemically etched at 65° C. for 5 minutes in alkaline permanganatesolution (M-Permanganate P, Product Code No. 79223) available fromMacDermid Inc. of Waterbury, Conn., USA. Following etching, the sampleswere rinsed in deionized water and submerged in neutralizer solution(M-Neutralize, Product Code No. 79225 also available from MacDermidInc.) for 5 minutes at room temperature. After neutralizing, the sampleswere rinsed with deionized water and metalized using a commercialsilvering solution (available from Peacock Laboratories Inc., ofPhiladelphia, Pa., USA; average grain size˜28 nm) and coated with 20 μmof fine-grained Ni-58Fe (average grain size˜20 nm, CLTE: ˜2×10⁻⁶ K⁻¹)according to the process of US 2005/0205425, published Sep. 22, 2005,the whole of which is incorporated herein by reference.

The metal clad articles had a yield strength of 44.6 MPa, an ultimatetensile strength of 47.3 MPa, a Young's modulus of 2.4 GPa and anelastic limit of 1.8%.

One of the panels was then subjected to a post-coating curing treatmentconsisting of heat treating the sample in a drying oven for anadditional 2 hours at 50° C. to fully cure the adhesive film. Pull-offand peel adhesion strength of the coatings on the two samples was thenmeasured following ASTM D4541-02 “Standard Test Method for Pull-OffStrength of Coatings Using Portable Adhesion Testers” using the“PosiTest AT Adhesion Tester” available from the DeFelsko Corporation ofOgdensburg, N.Y., USA and ASTM 8533-85 (2004) “Standard Test Method forPeel Strength of Metal Electroplated Plastics” using an Instron 3365testing machine equipped with the 90 degree peel test fixture, and a 5KN load cell, available from Instron Corporation, Norwood, Mass., USA.In all cases debanding occurred between the polymer material surface andthe immediately adjacent metal layer.

The pull-off and peel adhesion strength for the two samples issummarized in the table below. While the pull-off strength was high andessentially the same for both samples, the sample that received apost-coating heat treatment to fully cure the adhesive film displayed amuch higher peel strength (more than three fold). This exampleillustrates that pull off tests and peel tests are not interchangeableand do not produce results which are comparable. Specifically to thisexample, as highlighted, pull-off strength exceeding 1,000 psi isconsidered “excellent” for structural metal-clad polymer parts. A peelstrength value of 4 N/cm (Newton/cm), in the case of decorative metalcoatings on polymers, is considered to be “very poor”, whereas a peelstrength value of 12.5 N/cm is considered “excellent”,

TABLE 2 Pull-Off Strength Data (ASTM D4541-02) and Peel Strength Data(ASTM B533-85) for Samples With and Without Post Cure Heat Treatment.Pull-off Strength (ASTM Peel Strength (ASTM D4541-02) [psi] B533-85)[N/cm] Sample 1 without post- 1075 4.0 cure heat treatment Sample 2 withpost- 1100 12.5 cure heat treatment

Similar results were obtained when the intermediate layer comprised“electroless Ni”, available from various commercial vendors andconsisting of amorphous Ni—P, with a P content ranging from 2-15%,including Ni-7P available from MacDermid Inc., Waterbury, Conn., USA.

Working Example II Fine-Grained Ni Coated Graphite Reinforced CompositeActivated by Mechanical Abrasion

Graphite fiber/epoxy sheets (6 mm thick) were sourced from NewportAdhesives and Composites, Irvine, Calif., USA, and were cut into 5 cm by5 cm coupons. The surface of the coupons was mechanically ground usingP1000 sandpaper exposing carbon fibers. The CLTE of the coupon in theplane was 5×10⁻⁶ K⁻¹ and normal to the plane 60×10⁻⁶ K⁻¹. After surfacepreparation the surface roughness of the coupons was determined to beRa˜2.0 micron and Ry_(max)˜10.0 micron. Microscope analysis revealedthat the anchoring structures predominately included cross-hatchedgrooves and their population amounted to about 1,000 per cm. The couponswere encapsulated to a coating thickness of ˜50 micron by depositingfine-grained Ni-20Fe alloys (average grain size˜20 nm, CLTE: ˜11×10⁻⁶K⁻¹) from a modified Watts nickel bath and using a Dynatronix (DynanetPDPR 20-30-100) pulse power supply as described in US 2006/0135281-A1,published Jun. 22, 2006, the whole of which is incorporated herein byreference.

The metal clad articles had a yield strength of 606 MPa, an ultimatetensile strength of 614 MPa, a Young's modulus of 71 GPa and an elasticlimit of 0.9%.

Coated samples were exposed to a thermal cycling test which involvesvertical submersion into liquid nitrogen (T=196° C.) for one minute,immediately followed by submersion in hot water (T=90° C.) for oneminute. After ten cycles the sample is inspected for delamination,blistering, cracks and the like and the relative displacement of thecoating determined. Thirty such thermal cycles were performed. Allsamples passed the liquid nitrogen/hot water cycling test withoutdelamination. In addition, another set of samples was exposed to 10thermal cycles according to the ANSI/ASTM specification 13604-75 section5.4 Thermal Cycling Test for Service Condition 4 (85° C. to −40° C.)without failure. Thereafter, the adhesion between the metallic layer andthe polymeric substrate was determined using ASTM D4541-02 Method Eusing the self alignment adhesion tester type V described in Annex A5,specifically the “PosiTest AT Adhesion Tester” available from theDeFelsko Corporation of Ogdensburg, N.Y., USA. The data are displayed inTable 3.

TABLE 3 Thermal Cycling/Adhesion Test Results ANSI/ASTM specificationPull-Off Strength Thermal Cycling Test B604-75 section ASTM D4541-02Min/Max Coating (−196/90° C.) 5.4 Thermal Cycling Method E after 10Substrate Chemistry Coating Performance Test/SC4; 10 cycles of ASTMSubstrate CLTE (Average CLTE after 10 cycles/Displacementcycles/Displacement B604-75/SC4 Chemistry [10⁻⁶K⁻¹] Grain Size in nm)[10⁻⁶K⁻¹] ΔL/L [%] ΔL/L [%] [psi] Graphite 5/60 80Ni-20Fe 11 Pass/~0Pass/~0 350 Fiber/Epoxy (15 nm) Composite

Working Example III Fine-Grained Ni-58Fe Coated Carbon Fiber ClothReinforced Bismaleimide Polymer Composite Activated by Various Chemicaland Anodically Assisted Chemical Etching Methods, Use of a MetalizingLayer

3.75×8.75 cm coupons were cut from an 6 mm thick fully cured conductivecarbon-fiber reinforced plastic (CFRP) sheet of HTM 512, a bismaleimidepre-impregnated carbon fiber cloth composite used in high temperatureresistant composite tooling available from the Advanced Composites GroupLtd. of Heanor, Derbyshire, United Kingdom. The CLTE of the substratematerial is 3×10⁻⁶ K⁻¹ in the plane and 70×10⁻⁶ K⁻¹ in the directionnormal to the plane. The initial substrate preparation procedure was asfollows: (i) mechanically abrading all exposed surfaces using 320 gritto a uniform finish, (ii) scrubbing with steel wool and Alconox cleaner,followed by a rinse in deionized water and (iii) rinsing withisopropanol, followed by drying. Thereafter the composite coupons wereprocessed in various etching solutions, namely an alkaline permanganateetch, a chromic acid etch, a sulfuric acid etch and a sodium hydroxideetch with and without anodic assist. Microscope analysis revealedanchoring structures which included cross-hatched grooves, cavities,pitted anchoring structures and protruding anchoring fibers and,depending on the sample, their population amounted to between about3,000 and about 25,000 per cm for the samples which passed the thermalcycling test. Subsequently, the samples were metalized using acommercial silvering solution (available from Peacock Laboratories Inc.,of Philadelphia, Pa., USA; average grain size 28 nm) and coated on oneside with a 50 μm thick layer of fine-grained Ni-58Fe (CLTE: ˜2×10⁻⁶K⁻¹, average grain size˜20 nm) according to US 2005/0205425, publishedSep. 22, 2005.

The metal clad articles had a yield strength of 604 MPa, an ultimatetensile strength of 608 MPa, a Young's modulus of 71 GPa and an elasticlimit of 0.9%.

Following plating, the adhesion strength was measured using ASTMD4541-02 Method E “Standard Test Method for Pull-Off Strength ofCoatings Using Portable Adhesion Testers” using the “PosiTest ATAdhesion Tester” made by DeFelsko Corporation of Ogdensburg, N.Y., USA.In all cases debonding occurred between the polymer material surface andthe adjacent metal layer. Samples were also exposed to 10 cyclesaccording to ANSI/ASTM specification B604-75 section 5.4, servicecondition 4.

For each different etch solution chemistry, CFRP samples were testedunder 3 different conditions: 1) passive dip in solution for 5 min, 2)anodically polarized at 50 mA/cm² for 5 min, and 3) anodically polarizedat 100 mA/cm² for 5 min. Following etching the samples were neutralized,as appropriate and then rinsed in deionized water and the resulting massloss from etching was documented.

The etch compositions, etching conditions, mass loss during etching andadhesion strength after etching are shown in the Tables 4-7 below. Inthis experiment only the permanganate etch under all conditions testedand the sulfuric acid control etch were found to result in a weightloss. The slight increase in mass in the other samples may be a resultof “swelling” (absorption of liquid) during etching which is known tooccur with various polymer substrates including fiber reinforced epoxycomposites.

In all etch solutions investigated a significant increase in adhesionstrength is obtained (>30%) by applying an anodic current assist duringetching without any increase in etching time. The adhesion strength wasfound to increase with increased anodic assisted etch current density(100 mA/cm² compared to 50 mA/cm²). The oxidizing etch solutions(permanganate and chromic) were found to provide the highest adhesionvalues.

All samples were also exposed to 10 cycles according to ANSI/ASTMspecification B604-75 section 5.4, service condition 4 and all samples,except for the sulfuric acid etch and NaOH etch for dipping only, passedthe test.

TABLE 4 Permanganate Etch Solution Type Chemical Composition MacDermidM-Permanganate: 60 g/L Permanganate Etch M-79224: 60 g/L 5 min @ 45° C.D.I. Water: 940 g/L Thermal Cycling Test (ANSI/ASTM B604-75 section5.4); Adhesion Service Condition 4, (ASTM D4541- 10 Cycles/ Etching Type02 Method E) [psi] Displacement ΔL/L [%] Dip only 433 Pass/~0 Dip &Anodic Etch @ 668 Pass/~0 50 mA/cm² Dip & Anodic Etch @ 1069  Pass/~0100 mA/cm²

TABLE 5 Sulfuric Acid Etch Solution Type Chemical Composition SulfuricAcid Etch H₂SO₄: 5% (in D.I. water) 5 min @ 25° C. Thermal Cycling Test(ANSI/ASTM B604-75 section 5.4); Adhesion Service Condition 4, (ASTMD4541- 10 Cycles/ Etching Type 02 Method E) [psi] Displacement ΔL/L [%]Dip only 169 Failure/delamination Dip & Anodic Etch @ 227 Pass/~0 50mA/cm² Dip & Anodic Etch @ 328 Pass/~0 100 mA/cm²

TABLE 6 Sodium Hydroxide Etch Solution Type Chemical Composition SodiumHydroxide NaOH: 25% (in D.I. water) Etch 5 min @ 25° C. Thermal CyclingTest (ANSI/ASTM B604-75 section 5.4); Adhesion Service Condition 4,(ASTM D4541- 10 Cycles/ Etching Type 02 Method E) [psi] DisplacementΔL/L [%] Dip only 185 Failure/delamination Dip & Anodic Etch @ 409Pass/~0 50 mA/cm² Dip & Anodic Etch @ 643 Pass/~0 100 mA/cm²

TABLE 7 Chromic Acid Etch Solution Type Chemical Composition ChromicAcid Etch 5 min Chromic acid: 5% @ 50° C. Phosphoric acid: 15% Sulfuricacid: 55% (in D.I. water) Thermal Cycling Test (ANSI/ASTM B604-75section 5.4); Adhesion Service Condition 4, (ASTM D4541- 10 Cycles/Etching Type 02 Method E) [psi] Displacement ΔL/L [%] Dip only 408Pass/~0 Dip & Anodic Etch @ 772 Pass/~0 50 mA/cm² Dip & Anodic Etch @893 Pass/~0 100 mA/cm²

Working Example IV Graphite or Glass-Filled Polymeric CompositesActivated by Acid Etching and Coated with an Amorphous Ni-Based MetallicLayer or Coated with an Intermediate Conductive Layer and a Fine-GrainedNi Layer

5 cm by 5 cm coupons (thickness 2 mm) of various substrates weresuitable pretreated using a chromic acid etch solution as per WorkingExample III Table 7 and coated with various fine-grained materialsavailable from Integran Technologies Inc. (www.integran.com; Toronto,Canada) to a metallic layer thickness of micron. Substrate materialsincluded graphite/epoxy sourced from Newport Adhesives and Composites,Irvine, Calif., USA and glass fiber/polyamide composite coupons sourcedfrom BASF, Florham Park, N.J. USA. After appropriate chemical activation(chromic acid etch according to Table 7, dip only) all samples subjectedto electroplating were metalized using a commercial silvering solution(available from Peacock Laboratories Inc., of Philadelphia, Pa., USA;average grain size 28 nm). Microscope analysis revealed anchoringstructures that included cross-hatched grooves, cavities, pittedanchoring structures and protruding anchoring fibers and, depending onthe sample, their population amounted to between about 3,000 and about10,000 per cm. Subsequently, fine-grained Ni-based metallic layers weredeposited from a modified Watts bath as described in US 2005/0205425 A1,published Sep. 22, 2005. Amorphous Ni-based layers (˜20 micron thickNi-7P) were deposited directly onto the etched polymeric substratesusing an electroless nickel bath available from MacDermid Inc.,Waterbury, Conn., USA.

Table 8 summarizes the mechanical properties of the metal clad polymerarticles.

TABLE 8 Mechanical Properties of the metal clad polymer articles. YieldUltimate Young's Substrate (2 mm Coating Chemistry Strength TensileModulus Elastic thick) (20 micron thick) [MPa] Strength [MPa] [GPa]Limit [%] Glass Ni—7P (amorphous) 146 146 6.6 2.2 Fiber/PolyamideWithout Ag Composite metalizing layer Glass Ni (15 nm) 148 152 7.4 2.0Fiber/Polyamide With Ag metalizing Composite layer Glass 50Ni—50Fe (20nm) 150 154 7.0 2.1 Fiber/Polyamide With Ag metalizing Composite layerGraphite Ni—7P (amorphous) 601 601 70 0.9 Fiber/Epoxy Without AgComposite metalizing layer Graphite Ni (15 nm) 603 608 71 0.9Fiber/Epoxy With Ag metalizing Composite layer Graphite 50Ni—50Fe (20nm) 605 610 70 0.9 Fiber/Epoxy With Ag metalizing Composite layer

The coated samples were exposed to the thermal cycling test describedabove. The adhesion strength was measured using ASTM D4541-02 Method Eusing the “PosiTest AT Adhesion Tester” available from the DeFelskoCorporation of Ogdensburg, N.Y., USA. In all cases debonding occurredbetween the polymer material surface and the immediately adjacent metallayer. The data displayed in Table 9 indicate that acceptable thermalcycling performance is achieved. All samples were also exposed to 10cycles according to ANSI/ASTM specification B604-75 section 5.4, servicecondition 4 without failure.

TABLE 9 Thermal Cycling/Adhesion Test Results Thermal Cycling TestPull-Off (−196 to 90° C.) Strength Min/Max Performance ASTM SubstrateCoating Chemistry Coating after 10 cycles/ D4541-02 Substrate CLTE(Average grain size CLTE Displacement Method E Chemistry [10⁻⁶K⁻¹] innm) [10⁻⁶K⁻¹] ΔL/L [%] [psi] Glass 20/110 Ni—7P (amorphous) 20 Pass/~0300 Fiber/Polyamide Without Ag Composite metalizing layer Glass 20/110Ni (15 nm) 13 Pass/~0 300 Fiber/Polyamide With Ag metalizing Compositelayer Glass 20/110 50Ni—50Fe (20 nm) 10 Pass/~0 300 Fiber/Polyamide WithAg metalizing Composite layer Graphite 5/55 Ni—7P (amorphous) 20 Pass/~0620 Fiber/Epoxy Without Ag Composite metalizing layer Graphite 5/55 Ni(15 nm) 13 Pass/~0 620 Fiber/Epoxy With Ag metalizing Composite layerGraphite 5/55 50Ni—50Fe (20 nm) 10 Pass/~0 620 Fiber/Epoxy With Agmetalizing Composite layer

Working Example V Coating of Fully-Cured and Partially-Cured GraphiteReinforced Polymer Composites with a Silver (Ag) Intermediate Layer anda Fine-Gained Ni Layer, Including Heat-Treatment of the Partially-CuredCoated Part

Three 15×15 cm samples of 6 mm thick conductive carbon-fiber reinforcedplastic (CFRP) sheet (CLTE: in the plane 3×10⁻⁶ K⁻¹ and CLTE: ˜60×10⁻⁶K⁻¹ normal to the plane) were obtained from Janicki Industries ofSedro-Wooley, Wash., USA. Two of the panels were only “partially” cured,while the third panel was “fully” cured. The coupons were ground on oneside with 80 grit SiC paper to a consistent surface roughness, cleanedwith Alconox, (a surfactant available from Alconox Inc. obtainable fromOlympic Trading Co. of St. Louis, Mo., USA) and steel wool, followed byultrasonically cleaning in deionized water for 5 minutes. The sampleswas then rinsed in isopropanol, dried and degreased with1,2-dichloroethane to remove any residual oils and/or films.

The CFRP panels were then chemically etched in a standard acidsulfochromic etch solution consisting of 300 g/L chromic acid and 250g/l sulfuric acid in deionized water. After surface preparation thesurface roughness of the coupons was determined to be Ra˜2.0 micron andRy_(max)˜10.0 micron. Microscope analysis revealed that the anchoringstructures included cavities and pitted anchoring structures and theirpopulation ranged from about 1,000 to about 25,000 per cm. Followingetching, the samples were rinsed in deionized water and submerged inneutralizer solution consisting of 5 g/l of sodium metabisulfite for 5minutes at room temperature. After neutralizing, the samples were rinsedwith deionized water and metalized using a commercial silvering solution(available from Peacock Laboratories Inc., of Philadelphia, Pa., USA;average grain size 28 nm) and coated with 50 μm of fine-gained Ni(average grain size˜15 nm, CLTE: ˜13×10⁻⁶ K⁻¹) according to the processof US 2005/0205425 A1, published Sep. 22, 2005.

The metal clad articles had a yield strength of 602 MPa, an ultimatetensile strength of 606 MPa, a Young's modulus of 7.4 GPa and an elasticlimit of 0.9%.

One of the panels was then subjected to a post-coating heat-treatment ina drying oven for an additional 2 hours at 177° C. to fully cure thepartially cured panel. The pull-off adhesion strength of the coatings ofthe three CFRP samples was then measured following ASTM D4541-02“Standard Test Method for Pull-Off Strength of Coatings Using PortableAdhesion Testers” using the “PosiTest AT Adhesion Tester” available fromthe DeFelsko Corporation of Ogdensburg, N.Y., USA.

The pull-off adhesion strength for the three samples is summarized inthe Table 10. The pull-off strength for the “partially” cured sample wasfound to be significantly higher than that of the “fully” cured sample.The data also shows that a further increase in adhesion strength can beobtained by fully curing the “partially” cured CFRP panel after themetal coating. All samples were also exposed to 10 cycles according toANSI/ASTM specification B604-75 section 5.4, service condition 4 withoutfailure.

TABLE 10 Pull-Off Strength Data (ASTM D4541-02) for Samples. ThermalCycling Test (ANSI/ASTM B604-75 section 5.4); Service Pull-off StrengthCondition 4, (ASTM D4541-02) 10 Cycles/ Sample Information [psi]Displacement ΔL/L [%] Coating on fully cured 490 Pass/~0 CFRP-substrateCoating on partially 1542 Pass/~0 cured CFRP-substrate Coating onpartially 2078 Pass/~0 cured CFRP-substrate with post-plate heattreatment (2 hours at 177° C.)

Working Example VI Glass-Filled Polymer Composites Activated by AcidEtching and Coated with an Amorphous Ni-Based Intermediate ConductiveLayer and a Fine-Grained Ni Layer, Followed by Post Plate Heat-Treatment

5 cm by 5 cm coupons (thickness 2 mm) were cut from a commerciallyavailable 14% glass-filled polyamide substrate (Caspron®, BASF, FlorhamPark, N.J., USA.). The CLTE of the coupon in the plane was 32×10⁻⁶ K⁻¹and normal to the plane 70×10⁻⁶ K⁻¹. Samples were suitable pretreatedusing a chromic acid etch solution as per Working Example III Table 7(dip only). After neutralizing, the samples were rinsed with deionizedwater and metalized using a commercial amorphous electroless Ni-7Pcoating available from MacDermid Inc. of Waterbury, Conn., USA andthereafter coated with 20 μm thick fine-grained nickel (average grainsize˜20 nm, CTLE 13×10⁻⁶ K⁻¹) according to the process of US2005/0205425 A1, published Sep. 22, 2005, available from IntegranTechnologies Inc. (www.integran.com; Toronto, Canada).

The metal clad articles had a yield strength of 148 MPa, an ultimatetensile strength of 152 MPa, a Young's modulus of 7.4 GPa and an elasticlimit of 2.0%.

Microscope analysis revealed that anchoring structures includedcross-hatched grooves, cavities, pitted anchoring structures andprotruding anchoring fibers and amounted to between about 10,000 and15,000 per cm. Selected samples were heat treated at 80° C. and theadhesion and thermal cycling performance determined. The peel andpull-off adhesion strength of the samples was then measured followingASTM D4541-02 “Standard Test Method for Pull-Off Strength of CoatingsUsing Portable Adhesion Testers” and ASTM B533-85 (2004) “Standard TestMethod for Peel Strength of Metal Electroplated Plastics” using anInstron 3365 testing machine equipped with the 90 degree peel testfixture, and a 5KN load cell, available from Instron Corporation,Norwood, Mass., USA. In all cases debonding occurred between the polymermaterial surface and the immediately adjacent metal layer. The datadisplayed in Table 11 indicate that acceptable thermal cyclingperformance is achieved. All samples were also exposed to 10 cyclesaccording to ANSI/ASTM specification B604-75 section 5.4, servicecondition 4 without failure. It is noted that post-platingheat-treatment modestly enhances the pull-off strength whereas the peelstrength drastically deteriorates. As highlighted above and illustratedin Example 1 there is no correlation between pull-off and peel strengthdata.

TABLE 11 Thermal Cycling/Adhesion Test Results Thermal Cycling Test Post(ANSI/ASTM B604-75 Min/Max Coating Plating Pull-Off section 5.4);Service Substrate Chemistry Coating Heat-Treatment Strength PeelStrength Condition 4, 10 CLTE (Average CLTE Duration at ASTM D4541-02(ASTM B533-85) Cycles/Displacement [10⁻⁶K⁻¹] grain size in nm) [10⁻⁶K⁻¹]80° C. [hrs] Method E [psi] [N/cm] ΔL/L [%] 32/70 Ni (15 nm) 13 0 862 9Pass/~0 With NiP metalizing layer 32/70 Ni (15 nm) 13 1 932 7 Pass/~0With NiP metalizing layer 32/70 Ni (15 nm) 13 2 885 5 Pass/~0 With NiPmetalizing layer

Working Example VII Fine-Grained Co—P Metal Layer with a Rough SurfaceProduced Electrochemically Prior to Applying a Polymer Based BackingLayer

A metal-clad polymer part was fabricated from two components, namely aface plate comprised of a durable electroformed fine-grained Co-2P alloy(15 nm average grain size, CLTE in plane and normal to it: ˜15×10⁻⁶K⁻¹), and a polymer backing structure comprising a thermoplastic polymer(polypropylene, CLTE in plane and normal to it: ˜85×10⁻⁶ K⁻¹). Ratherthan coating the activated polymer substrate with a fine-grained metal,the layers were applied in reverse order, namely the first step entailedplating the fine-grained Co-2P alloy layer (average grain size 15 nm)according to US 2005/0205425 A1, published Sep. 22, 2005, onto apolished temporary titanium substrate. After building up thefine-grained metallic layer to a thickness of approximately 250 microns,the applied current density was raised substantially to deposit a rough“bonding surface” with anchoring structures including protrusions anddendritic nodules with a porous substructure and, depending on thesample, their population count ranged between about 100 and about 3,000per cm. After plating, the surface roughness of the metallic layer, toserve as interface with the polymeric layer, was determined to be Ra˜125micron and Ry_(max)˜250 micron. As outlined, the important feature ofthe design is to purposely create a rough surface on the backside of thefaceplate which allows for excellent adhesion between the metalfaceplate and the polymer backing structure. A polypropylene substratebacking was applied to the rough side of the fine-grained metal layer ina subsequent step by compression molding to an ultimate thickness of 6mm. Metal-clad polymer samples exposed to 10 cycles according ANSI/ASTMspecification B604-75 section 5.4, service condition 4, did not fail andthe adhesion strength values that have been obtained using ASTM D4541-02Method B all exceeded 300 psi. The metal clad articles had a yieldstrength of 96 MPa, an ultimate tensile strength of 113 MPa, a Young'smodulus of 6.5 GPa and an elastic limit of 1.0%.

Working Example VIII Molded Polypropylene Using Embossing Die MoldInserts, Activated by Chemical Etching and Coated with an AmorphousNi-Based Intermediate Conductive Layer Followed by Coating aFine-Grained Cu Layer, a Fine-Grained Ni—Co—Fe Metal-Layer

Molded cell phone casings (˜5 cm by 10 cm, thickness 1 mm) wereinjection molded from a commercially available polypropylene (RTP-141Hprovided by the RTP Company, Winona, Minn. 55987, USA). The CLTE in alldirections was about 65-80×10⁻⁶ K⁻¹. Before use, the injection moldcavity was ground back and suitably lined with 500 micron thick,fine-grained Ni embossing die inserts. The embossing die inserts wereelectroplated as described in US 2005/0205425 A1, published Sep. 22,2005, available from Integran Technologies Inc. (www.integran.com;Toronto, Canada). The molding surfaces of the fine-grained Ni insertswere shot-peened (180 grit Al₂O₃ at 87 psi at a distance of 10 cm) andchemically etched in 5% HNO₃ (30 minutes at room temperature) asdescribed in copending application by Victor, entitled “Metallicarticles With Hydrophobic Surfaces” (Integran 6236), to create thedesired embossing die surface features for embossing the anchoringstructures into the molded polymer housings. The embossing insertsimprinted the anchoring structures on the entire inner and outersurfaces of the cell phone housings. After forming, selected molded cellphone cases were also suitable pretreated on the surface to be platedusing a chromic acid etch solution as per Working Example Table 7(sulfochromic etch, dip only). The outside casings and all other areasnot to be plated were masked off and not etched. After neutralizing, thesamples were rinsed with deionized water and metalized using acommercial amorphous electroless Ni-7P coating available from MacDermidInc. of Waterbury, Conn., USA and thereafter coated with 12.5 μm thickfine-grained Cu (average grain size 4 micron, CTLE 17×10⁻⁶ K⁻¹)according to the electrodeposition process of WO 2009/076,777 publishedJun. 25, 2009, available from Integran Technologies Inc.(www.integran.com; Toronto, Canada), followed by 75 μm of fine-grained40Ni-40Co-20Fe (average grain size˜20 nm, CTLE 13×10⁻⁶ K⁻¹) according tothe process of US 2005/0205425 A1, published Sep. 22, 2005, availablefrom Integran Technologies Inc. (www.integran.com; Toronto, Canada). Asa result of the embossed polymer surface the metal coating had a satinsurface finish. The texturing greatly reduced the risk of slipping anddropping the part and rendered it comfortable to firmly grip and hold.

Microscope analysis revealed that anchoring structures included micro-and nanostructured protrusions amounting to between about 10,000 and15,000 per cm. The pull-off strength of the samples was then measuredfollowing ASTM D4541-02 “Standard Test Method for Pull-Off Strength ofCoatings Using Portable Adhesion Testers”. In all cases debondingoccurred between the polymer material surface and the immediatelyadjacent metal layer. The data displayed in Table 12 indicate thatacceptable thermal cycling performance is achieved. All samples werealso exposed to 10 cycles according to ANSI/ASTM specification B604-75section 5.4, service condition 4 without failure.

TABLE 12 Cell Phone Housing Properties, Adhesion and Thermal CyclingResults. Pull-Off Strength Thermal Cycling Test Coating ASTM (ANSI/ASTMB604-75 Min/Max Chemistry Coating Coating D4541-02 section 5.4); ServiceCLTE (Average grain CLTE thickness Method E Condition 4, 10 Cycles;[10⁻⁶K⁻¹] size in nm) [10⁻⁶K⁻¹] [μm] [psi] Displacement ΔL/L [%] 13/80Polypropylene 65-80 N/A- 1,550 Pass/~0 Embossed Substrate Ni—8P 13 <1(amorphous) Cu (4,000 nm) 17 12.5 40Ni—40Co—20Fe 13 75 (20 nm)

When applying the metallic layer on the outside of the housing a thinlayer of conventional hard chromium (<1 μm) was electroplated fordecorative purposes. Selected samples employed a second Cu layer (25 μm)after the application of the NiCoFe layer to enhance thermalconductivity and heat dissipation when used in the device. The Ni—Fe—Colayer provides for EMI and RFI shielding. Alternative electroplated EMIor RFI shielding layers included Ni, Co and Fe or any of their alloysincluding Ni-20Fe and Ni-50Fe. Selected samples were also plated with 10micron thick Sn layer for corrosion protection and selected samples didnot contain a Cr flash.

It was surprisingly noticed that the uncoated outside layer of thepolymer casings imprinted with the embossed anchoring structuresexhibited a significant increase in the contact angle for water, i.e.,the polymer surface became more water repellent, at timessuperhydrophobic and self cleaning as highlighted in Table 13. Thecontact angle was measured by placing multiple 5 μl droplets ofdeionized water on a flat sample surface and taking a picture with astereoscope at 15× magnification. Contact angle measurements were takenfrom the digitally captured images using Image-pro software. Only a verymodest increase in the contact angle is noticed when the “as molded”smooth polymer surface is etched) (3°-6°, however, a substantial contactangle increase is noted after embossing the unetched polymer surfacewith various embossing dies (31°-60° contact angle increase).

TABLE 13 Contact angle of unplated and plated PP surfaces with andwithout embossing with anchoring structures. Contact Angle of PP beforeand after embossing with various Nanometal dies Sample Information[degrees] Smooth Molded PP Surface 97 Plated Smooth Molded PP 69 SurfaceImprinted Molded PP Surface 151 Plated Imprinted Surface 64

Working Example IX Molded Polyamide Using Embossing Die Mold Inserts,Activated by Chemical Etching and Coated with an Amorphous Cu-BasedIntermediate Conductive Layer Followed by Coating with VariousFine-Grained Layers

Polymer cell phone casings (˜5 cm by 10 cm, thickness 1 mm) wereinjection molded and imprinted as described in Example VIII using apolyamide polymer (Durethan BKV130, supplied by Lanxess Corp.,Pittsburgh, Pa., USA). The cell phone casings were etched using PM 847,a semi-aqueous acid etchant containing glycol provided by Rohm and HaasElectronic Materials (Freeport, N.Y., USA) and metalized using acommercial amorphous electroless Cu coating (M-Copper 15) available fromMacDermid Inc. of Waterbury, Conn., USA. The polymer casings weretotally encapsulated with the applied coatings. Coating thickness,compositions, pull-off and thermal cycling performance data are providedin Table 14. Microscope analysis revealed that anchoring structuresincluded micro- and nanostructured protrusions amounting to betweenabout 10,000 and 15,000 per cm.

For comparison purposes cell phone casings were molded using a “smoothmold” without the imprinted surface, otherwise processed as indicatedfor sample 1 and tested. The average pull-off strength was determined tobe 485±17 psi and the thermal cycling test was passed withoutdelamination and with 0% displacement. Peel strength was determined aswell for all samples using ASTM B533-85 (2004) “Standard Test Method forPeel Strength of Metal Electroplated Plastics” using an Instron 3365testing machine equipped with the 90 degree peel test fixture, and a 5KNload cell, available from Instron Corporation, Norwood, Mass., USA, andno correlation between peel and pull-off data was noticed. The peelstrength for embossed samples could not even be determined as the metalcoating failed (ripped) before the coating separated from the polymer.

TABLE 14 Cell Phone Housing Design Variations; Adhesion & Cycling TestResults for Imprinted Polymer Substrates Thermal Cycling Test (ANSI/ASTMCoating B604-75 section 5.4); Min/Max Chemistry Coating Coating Pull-OffStrength Service Condition 4, 10 CLTE (Average CLTE thickness ASTMD4541-02 Cycles/Displacement [10⁻⁶K⁻¹] grain size in nm) Purpose[10⁻⁶K⁻¹] [μm] Method E [psi] ΔL/L [%] Sample 1 Polyamide Flat Substrate20-100 N/A 485 Pass/~0 13/100 Cu- Metalizing Layer 17 <1 (amorphous) Cu(4,000 nm) Electrical conductivity 17 12.5 and heat dissipation Ni-20Fe(20 EMI & RFI shielding 13 25 nm) Cu (400 nm) Heat dissipation and 17 10antimicrobial properties Sample 2 Polyamide Embossed Substrate 20-100N/A 700 Pass/~0 6/100 Cu Metalizing Layer 17 <1 (amorphous) Cu (4,000nm) Electrical conductivity 17 12.5 and heat dissipation Ni-20Fe (20 EMI& RFI shielding 13 25 nm) Cr Decorative 6 <1 Sample 3 Polyamide EmbossedSubstrate 20-100 N/A 700 Pass/~0 13/100 Cu Metalizing Layer 17 <1(amorphous) Cu (4,000 nm) Electrical conductivity 17 12.5 and heatdissipation Ni-20Fe (20 EMI & RFI shielding 13 25 nm) paint Decorativeand 100 5 superhydrophobic/self- cleaning Sample 4 Polyamide EmbossedSubstrate 20-100 N/A 700 Pass/~0 13/100 Cu Metalizing Layer 17 <1(amorphous) Cu (4,000 nm) Electrical conductivity 17 12.5 and heatdissipation Ni-20Fe (20 EMI & RFI shielding 13 25 nm) Cu (400 μm) Heatdissipation, 20 10 PTFE MMC antimicrobial properties andsuperhydrophobic/self- cleaning

Working Example X Various Molded Polymers with and without Embossing byCompression Molding, Activated by Chemical Etching and Coated with anAmorphous Ni-Based Intermediate Conductive Layer Followed by Coatingwith Fine-Grained Ni

A number of polymer golf club head face-plates were injection molded (3cm by 8 cm, thickness 1 mm) using a polished mold surface. Plates weremolded from two polymers: (i) glass filled polyamide polymer (DurethanBKV130, supplied by Lanxess Corp., Pittsburgh, Pa., USA) and (ii)polypropylene (RTP-141H provided by the RTP Company, Winona, Minn.55987, USA). Only one side of the surface of each face plate wasembossed with an embossing die insert made as described in Example VIII.Embossing took place at 200° C. using compression molding. In addition,a set of faceplates was heat treated at 200° C. without any embossing toevaluate the effect of the applied post heat-treatment of the moldedpolymer sample on adhesion. Thereafter, all polyamide face plates wereetched as illustrated in Example IX (glycol etch), polypropylene faceplates were etched as in Example VIII (sulfochromic etch, dip only).After etching all samples were metalized and totally encapsulated withthe applied coatings. Coating thickness, composition and CTLE values areprovided in Table 15. Adhesion and thermal cycling performance weremeasured on the embossed surface, where applicable, as well as the flatback-surface by performing pull-off and peel tests, as described. Thesedata are also displayed in Table 16. Microscope analysis of the embossedsurfaces revealed that anchoring structures included micro- andnanostructured protrusions amounting to between about 10,000 and 15,000per cm.

TABLE 15 Faceplate Design Information Substrate/Coating Min/MaxChemistry Coating CLTE (Average grain CLTE Thickness [10⁻⁶K⁻¹] size innm) Purpose [10⁻⁶K⁻¹] [μm] 13/100 Polyamide (filled) Substrate 20-1001,000 Ni—8P Metalizing layer 17 <1 (amorphous) Ni (25 nm) Strength and13 20 wear resistance 13/80  Polypropylene Substrate 65-80  1,000(filled) Ni—8P Metalizing layer 17 <1 (amorphous) Ni (25 nm) Strengthand 13 20 wear resistance

TABLE 16 Adhesion and Temperature Cycling Test Results for Flat andEmbossed Polymer Substrates Thermal Cycling Pull-Off Test (ANSI/ASTMStrength B604-75 section 5.4); ASTM Service Condition 4, PolymerMetal-Clad D4541-02 10 Surface Polymer Heat Method E Cycles/DisplacementSample Treatment Treatment at 200° C. [psi] ΔL/L [%] Polyamide N/A-flatN/A 596 ± 16 Pass/~0 surface Polyamide N/A-flat Yes 362 ± 6  Pass/~0surface Polyamide Embossed Yes 699 ± 10 Pass/~0 Polypropylene N/A-flatN/A 1,018 ± 33   Pass/~0 surface Polypropylene N/A-flat Yes 1,167 ± 250 Pass/~0 surface Polypropylene Embossed Yes 1,535 ± 185  Pass/~0

The peel strength was measured as well and ranged from as low as 2.5N/cmto an upper limit which could not be determined as the metal coatingfailed (ripped) before the coating separated from the polymer. Nocorrelation between pull-off and peel adhesion values was observed. Thedata reveal a significant increase in adhesion strength for sampleswhich, before exposure to chemical etching, were imprinted. It is alsonoticeable, that heat-treatment (HT) of the plated not-imprintedpolyamide samples significantly reduced the adhesion, while, in the caseof not-imprinted polypropylene, the heat-treatment did not significantlyalter adhesion.

VARIATIONS

The foregoing description of the invention has been presented describingcertain operable and preferred embodiments. It is not intended that theinvention should be so limited since variations and modificationsthereof will be obvious to those skilled in the art, all of which arewithin the spirit and scope of the invention.

1. A sporting goods article comprising: (i) a polymeric material whichat room temperature has a coefficient of linear thermal expansion in therange between 30×10⁻⁶ K⁻¹ and 250×10⁻⁶ K⁻¹ in at least one direction;and (ii) a metallic material having a microstructure which isfine-grained with an average grain size between 2 and 500 nm and/or anamorphous microstructure, the metallic material being in the form of ametallic layer having a thickness between 10 microns and 500 microns anda coefficient of linear thermal expansion at room temperature in alldirections in the range between −5.0×10⁻⁶ K⁻¹ and 25×10⁻⁶ K⁻¹; (iii)with at least one intermediate layer between the polymeric material andthe metallic material; (iv) an interface between the polymeric materialand one intermediate layer and an interface between one intermediatelayer and the metallic material; (v) anchoring structures at saidinterfaces comprising recesses and/or protrusions to increase theinterface area and provide enhanced physical bond between adjacentlayers; (vi) said sporting goods article exhibiting a pull-off strengthbetween the polymeric material and the metallic material exceeding 200psi as determined by ASTM D4541-02 Method A-E; and (vii) said sportinggoods article or portions thereof containing said metallic materialhaving a yield strength and/or ultimate tensile strength of between 10and 7,500 MPa and an elastic limit between 0.5 and 30%.
 2. The sportsarticle according to claim 1 exhibiting no delamination after saidsporting goods article has been exposed to at least one temperaturecycle according to ASTM B553-71 service condition 1, 2, 3 or
 4. 3. Thesporting goods article according to claim 1 wherein the surfaceroughness of the polymeric material and/or the metallic material at anyof said interfaces is in the range of Ra=1 micron and Ra=500 microns. 4.The sporting goods article according to claim 1 wherein said metallicmaterial comprises at least one metal selected from the group consistingof Al, Co, Cr, Cu, Fe, Ni, Mo, Sn, Ti, W, and Zn.
 5. The sporting goodsarticle according to claim 1, wherein said polymeric material comprisesat least one material selected from the group consisting of epoxyresins, phenolic resins, polyester resins, urea resins, melamine resins,and thermoplastic polymers.
 6. The sporting goods article according toclaim 1 wherein said metallic material represents between 5 and 95% ofthe total weight of the sporting goods article.
 7. The sporting goodsarticle according to claim 1, wherein at least one intermediate layercomprises a polymeric material.
 8. The sporting goods article accordingto claim 7, wherein said at least one polymeric intermediate layer is anadhesive layer.
 9. The sporting goods article according to claim 7,wherein said at least one polymeric intermediate layer comprises anelastomer.
 10. The sporting goods article according to claim 7, whereinsaid at least one polymeric intermediate layer contains epoxy.
 11. Thesporting goods article according to claim 1 comprising at least oneintermediate layer which is conductive between said metallic materialand said polymeric material.
 12. The sporting goods article according toclaim 11, wherein said at least one conductive intermediate layercomprises at least one metal selected from the group consisting of Ag,Ni, Co and Cu.
 13. The sporting goods article according to claim 1,wherein said sporting goods article is selected from the groupconsisting of golf shafts, heads and faceplates, lacrosse sticks, hockeysticks, arrows, fishing poles, skiing and hiking pole shafts, skis andsnowboards as well as their components including bindings, racquets fortennis, squash, and badminton, baseball bats and bicycle parts.
 14. Thesporting goods article according to claim 1, wherein said fine-grainedand/or amorphous metallic material extends over at least part of theinner or outer surface of said polymeric material.
 15. The sportinggoods article according to claim 14 which is a hockey stick, andcomprises a polymeric substrate containing glass fibers and/or acarbon-containing material selected from the group consisting ofgraphite, graphite fibers, carbon, carbon fibers and carbon nanotubes.16. The hockey stick of claim 15, wherein said hockey stick contains atleast one intermediate layer between the polymeric material and themetallic material which is electrically conductive and comprises atleast one material selected from the group consisting of Cu, Ni, Co, Ag,and carbon and/or at least one adhesive layer.
 17. A hockey stickcomprising: (i) a polymeric material which at room temperature has acoefficient of linear thermal expansion in the range between 30×10⁻⁶ K⁻¹and 250×10⁻⁶ K⁻¹ in at least one direction and containing at least onematerial selected from the group consisting of glass fibers, graphite,graphite fibers, carbon, carbon fibers and carbon nanotubes; and (ii) ametallic material containing at least one metal selected from the groupconsisting of Cu, Co, Ni and Fe having a microstructure which isfine-grained with an average grain size between 2 and 500 nm and/or anamorphous microstructure, the metallic material being in the form of ametallic layer having a thickness between 10 microns and 500 microns anda coefficient of linear thermal expansion at room temperature in alldirections in the range between −5.0×10⁻⁶ K⁻¹ and 25×10⁻⁶ K⁻¹; (iii)with at least one intermediate layer comprising a polymer and/or atleast one intermediate layer which is electrically conductive comprisingat least one material selected from the group consisting of Cu, Ni, Co,Ag, and carbon between the polymeric material and the metallic material;(iv) an interface between the polymeric material and an intermediatelayer and an interface between an intermediate layer and the metallicmaterial; (v) anchoring structures at said interfaces comprisingrecesses and/or protrusions to increase the interface area and provideenhanced physical bond between adjacent layers; and (vi) said hockeystick exhibiting a pull-off strength between the polymeric material andthe metallic material exceeding 200 psi as determined by ASTM D4541-02Method A-E.
 18. The hockey stick of claim 17, wherein the surfaceroughness of the polymeric material and/or the metallic material at anyof said interfaces is in the range of Ra=1 micron and Ra=50 microns. 19.The hockey stick according to claim 17, wherein said metallic materialrepresents between 5 and 95% of the total weight of the hockey stick.20. The hockey stick according to claim 17 exhibiting no delaminationafter said article has been exposed to at least one temperature cycleaccording to ASTM B553-71 service condition 1, 2, 3 or 4.